There are so many of them that it feels like you kill one only to see three more seemingly appear out of nowhere.
It’s like a never-ending spawn of these gray and brown moths that makes you feel like you’re in a zombie apocalypse movie- except swap the zombies for miller moths. And a crowbar for a roll of newspaper.
(I haven’t been keeping up with my zombie flicks. Sorry.)
In this guide, you’ll learn about:
The basics about miller moths
Their insect profile
Why there are so many miller moths this year
How to get rid of them naturally
Ways to keep moths out of your home, garden, and plants
And more
By the end of this (very long) guide, you should have a solid base of knowledge to get rid of them for good.
And if you have any questions, feel free to post a comment on this page and I’ll help you out (as usual!) if I can.
Sounds good? Let’s send those miller moths back to the mills!
Sections
What’s a miller moth?
A miller moth (Acronicta leporine) is a nickname referring to a whole family of common nuisance moths found in the US.
It’s called “miller” because that’s the name that most often refers to the army cutworm moth, which is scientifically known as Euxoa auxiliaris.
So let’s get that out of the way- miller moths don’t refer to any specific type of moth.
But it DOES often refer to army cutworms.
When cutworms undergo pupation and emerge as adults, they’re known as miller moths.
It’s also important to note that army cutworms are the larvae. They’re worms, which can also be mistaken for caterpillars, maggots, and meal moths.
These are the “baby” form of miller moths, which feed on materials until it pupates into an adult, flying moth. These are both the same pest.
Other names
There are many other names for miller moths because of their strong presence in the Great Plains, Great Rockies, and Great Midwest US!
Some of the most common nicknames given to these buggers are:
Gypsy moth
Salt marsh moth
Tussock moth
Army cutworms
Army moths
Millers
Miller butterflies
Appearance – What do they look like?
Miller moths can vary in appearance, as there’s no single way to account for all their unique patterns, colors, and shapes.
Remember that “miller” doesn’t refer to ONE single moth- it’s a whole group of them.
This is why you can’t give a generic appearance profile of what they look like and apply it to all of them.
Although it commonly refers to the army cutworm, it can have other meanings as well.
However, here’s a description of how the army miller moth looks like, as it’s the most common one found in the US:
Light gray or brown color
Waves or triangles on the back
Light markings on the wings
1.2-2.0” wingspan
Kidney shaped marking on the forewings
White, gray, or brown wings
2 long antenna
Visible legs in the front half of their body
Dusty or flour-like wings that they leave behind
Scales that rub off on the wings
This is how you identify adult miller moths.
These flyers have a range of different patterns, so don’t expect a concrete way to identify them by this phenotype only.
Each moth will leave behind a dusty cover when touched. If you’ve ever squished one on your wall, you’ll notice that the dust will stain your surfaces and is very hard to clean.
Don’t squish or smack them. The best time to catch them is when they’re flying around in the air so they don’t stain any surfaces.
Identification of larvae
The larvae look like small caterpillars scattered with hairs. (By Lilly M – Own work, CC BY 2.5)
The larvae are similar to any other moth larvae. They’re light brown to silver gray and have darker heads. They can also be green with tiny hairs that are yellow or white.
They look like tiny caterpillars, worms, or maggots with segmented sections that have symmetrical spots on both sides of their body.
It’s not always easy to identify miller moths because they’re part of a large group of moths that are very similar in appearance to each other.
Use the tips regarding their appearance above for basic guidelines on pest ID. The larvae overwinter as a pupae and adults will fly at night between June to August.
When are they active?
Army cutworms are active during the night as seen from their migratory behaviors.
They use moonlight or other natural lights that exist in nature to conduct their long flight from the plains to the mountains and back.
When they see artificial lighting (such as those from your house), they get easily confused.
They’ll gravitate towards these lights during the night in a spiral pattern, which is why you’ll see them buzzing around your patio lights, table lamps, or lights inside your house if they get inside.
You won’t see them flying during the day unless they’re disturbed, as these are nocturnal creatures that are guided by celestial lighting in nature.
They’re not too “bright” so they get confused when they fly by your house and see a bunch of low glow lighting.
This is why turning OFF your lights can help steer them away from your property.
Lifecycle
The miller moth has a pretty standard lifecycle. The larvae worm will spend its entire spring/summer eating on crops and plants.
For the typical homeowner, garden veggies can be severely damaged from their high populations. The larvae continue to feed until late spring, which then they drop off their host plant and dig into the soil.
The soil provides them a safe chamber to burrow in and then pupate. After 3-6 weeks, the miller moth emerges from the soil and then starts its migration journey. The journey usually ends in the summertime.
The moth doesn’t fly directly to higher elevations in one fell swoop. They’ll take breaks during the flight and rest on cool plants, rocks, and other things. Miller moths also don’t mate during this flight, so no eggs are deposited.
This is why they won’t infest your house. Even if they get in, they’ll just fly around confused and dumbfounded.
When the fall comes, they’ll start to lay eggs in leaves, shrubs, and other dense foliage. In nature, miller moth eggs are found in weedy fields. Alfalfa is one of their favorite crops to eat and breed in.
Eggs will hatch within a few weeks and the cutworm larvae come out to feed. They continue to eat throughout the winter, unlike other moths.
Types of miller moths
Since the phrase is an umbrella term that covers a bunch of different moths found in the mid-US, it includes many different species.
Here are some of the most popular moths found in the Colorado and Rocky region:
Army cutworm
Cutworm moths
Army moths
Fall webworm moth
White-lined sphinx
Forest tent caterpillar moth
Isabella tiger moth
Hairstreaks
Salt marsh moth
Polyphemus moth
Tussock moth
Cecropia moth
Mourning cloak
What are miller moths attracted to?
Like other flying insects, miller moths exhibit a liking for lights!
Miller moths are attracted to food and shelter.
These are cool temperature moths that like dense vegetation, nectar-producing flowers, and undisturbed fields. They also like sugar, as the nectar provides.
They also do like light and will hover around it during the night.
What do miller moths eat?
Miller moths eat a variety of crops and dry goods.
You may have some of these growing in your garden or stored inside your house, which could be the reason why they’re hovering around you in the first place.
A miller moth infestation can be controlled by eliminating the food source, but this can be difficult. Finding the food isn’t always apparent.
But if you do manage to find it, you can toss it to eliminate their food source and they may leave your property.
Some foods that miller moths eat include:
Winter wheat
Weeds
Lawns
Alfafa
Crops
Nectar
Wheat fields
Turfgrass
Birch, hazel, beech, poplar, oak, willow, tobacco, alder, and white beam
Wood
Firelogs
Nectar from flowers
Sugar
During the summertime, army cutworms will feed on the nectar of plants. Because of this, they prefer flowering plants.
They can be found hiding in cooler areas under dense foliage, soil, rocks, or other natural or manmade structures.
The larvae hatch from eggs that are laid in weedy areas with high vegetation like alfalfa fields or dense weedy gardens. Lawns and forests are also good targets.
Where do they live?
Miller moths live all over the United States and some other countries including Europe, Spain, Italy, Scandinavia, Arctic circle, Norway, Africa, Scotland, and Bulgaria.
In the US, they’re most commonly found in Colorado, Nebraska, Kansas, Arizona, Wyoming, and New Mexico.
These pests have a preferred environment that they’ll inhabit, which is similar across all of these states. If you live in CO, you may have noticed that in 2020 and 2021 miller moths have been abundant everywhere!
Where do they come from?
They come from the great high plains across the US.
They migrated between the plains and the mountainous regions in the central US. Their migration range includes the Front Range of Colorado, Wyoming, Kansas, Oklahoma, and Nebraska.
Wherever there are army cutworms, there are millers. They can be so problematic that they fly into your car as soon as you drop the window or into your house when you prop the door or window. They’re crazy.
They prefer higher elevations during the summertime, so you may notice a drop in population if you’re in a lower elevation.
Where do they hide?
Plants that provide nectar with dense foliage are perfect.
Miller moths like to hide out of sight during the daytime in whatever they can find. In nature, they hide in dense bushes, leaves, or flowering plants.
They’re not picky as they’re migratory and won’t make it their permanent home. Inside the house, they don’t have those natural options, unless you have houseplants.
You may find them hiding in your curtains, drapes, rugs, carpet, walls, ceiling, or near light sources. Similar to many flying insects that are attracted to lights inside the house, miller moths are no different.
Unlike clothing beetles, miller moths won’t feed on fabrics inside the household. They also don’t eat most dry goods that may be around in your kitchen pantry.
Miller moths don’t bite humans, so they’re harmless. They’re nothing but a nuisance, especially when they fly into your face when you’re trying to binge on your favorite show.
The caterpillar larvae can actually help control weedy plants in some respect. But the adult miller moth is just a nuisance. They don’t infest your house and they don’t lay eggs inside.
During migration, they don’t breed or deposit eggs.
They don’t damage or eat furniture or household materials either. They eventually will escape your house or they’ll starve.
But if you have a lot of them at once, they can stain your things if you squish them or crush their fragile wings. They may also bring in other bugs that eat them into your property. You’ll probably find a lot of them near your windows, drapes, or places with wind currents.
Why do they stain walls?
The adults that come out of pupa will smudge a brownish stain. It looks like a teardrop shape and can be found on walls where the eggs are deposited.
When the adult comes out of the pupa, fluid is leaked from the pupa itself. This is what stains the walls. It can be removed with regular dish soap or surface cleaner.
Why are there so many miller moths?
Some seasons have shown high numbers of moths. Their flight usually lasts about 6 weeks and ends in July. However, this is when they’ll show their biggest numbers.
This is also when most people will report their presence because of their nuisance problems.
Some years are worse than others because of climate patterns. If the weather is cooler, this is favorable for miller moths, so you should expect a higher number of them.
It also matters whether the moths are heading towards the mountains or coming back from them. The return trip is generally shorter.
In the 2002 flight, there was a persistent drought, which brought these moths new flight patterns. They resided in the homes of people that had nectar-producing flowers. Gardens with sprinklers or fountains were prime targets.
In 2020, miller moths were seen everywhere, especially in CO. Conditions like overcast, drought, and warm weather all affect local climate and change their behavior.
Cool-weather is their primary attraction. When the conditions are favorable to them, they gravitate towards these environments.
Some years are worse than others. It all depends on what influences the outbreak of cutworms. Preferable conditions like cool weather, snow cover, natural predators, nectar, humidity, temperature, all influence how many miller moths you see.
Why do they migrate? And how?
Miller moths migrate because they seek an ideal temperature range and food availability.
There’s no scientific reason identified yet from research papers online, but a few of them suggest that these moths move from place to place in search of nectar.
They fly to areas with higher elevations because the temperature is also cooler when summer comes around.
Whatever the case, this is why you may find them in huge numbers all of a sudden in your garden, on the highway, or even inside your house.
Miller moths are unique from other cutworm spices after they pupate. Instead of remaining in the same soil patch for months after they hatch, these moths will migrate across the US.
The typical armyworm will stay in the same place for many seasons. The miller moth doesn’t.
It leaves shortly after. They migrate in batches and the total flight time may take up to 5 weeks. They start their journey in early June and this is usually when you see a lot of them everywhere. It seems that the local weather and environmental conditions determine when they begin their migration.
There are some years where these moths are especially crazy, such as 1991 and 2002. 2020 and 2021 both seem to have high numbers.
They migrate from the plains to the mountains in June, and then backward in the fall. Large populations of cutworms will lead to larger numbers of moths.
This is influenced by variables like temperature, natural predators, food availability, human intervention, overcrowding, shelter, etc.
How to get rid of miller moths naturally
Here are some ways you can naturally get rid of miller moths from your household.
They won’t all work for you, but once you find a DIY home remedy that does, scale it up.
Try out more than one simultaneously so you can find the solution quickly.
Even if you end up never getting rid of them, note that they can’t stay in your house forever.
They’ll eventually perish from starvation or find a way out on their own.
Turn off lights
Turn off or dim your patio, porch, pathway lights. Dim indoor or block inside lighting with blinds.
If you have lights on during the peak migration season (summer), millers may see your home as a temporary place to take shelter during their journey.
Summer is also when we have lights on late into the evening after the sun sets, so this doubly makes your home attractive to moths.
Consider turning off ALL lighting that you don’t need
Block out lights from leaking outdoors by using blinds or curtains
Dim lights if possible
Get rid of unnecessary outdoor lighting
This will help make your home less attractive to miller moths.
Replace bulbs with yellow ones
If you need your lighting, consider replacing the bulbs with yellow bulbs. These bulbs are less likely to attract insects that exhibit a liking for light (photoaxis).
There’s nothing special about them other than that they’re a bit warmer on the light spectrum. But it may be worth it if you’re constantly drawing with bugs getting inside your house.
Pest exclusion
You can stop meal moths for good by cleaning up your kitchen.
Practicing proper pest exclusion is key to preventing the infestation of your home from ALL bugs.
For those who don’t know, pest exclusion refers to the act of excluding bugs from entering your home in the first place. No bugs inside? No problem.
Of course, you can extend the term to include your garden, garage, ADU, outhouse, shed, etc. It’s the best way to prevent bugs and is more effective than any other method, yet it’s also often overlooked because it does involve some effort.
For starters, here are some pointers to go over and patch up or repair your property from pests:
As you can see, it does more than just prevent miller moths.
Keep the garden clean and tidy
A clean yard proves to be less attractive to pests.
This is important enough to require its own section.
As you know, the miller moths will stop at your house because it provides ample flowers for them to eat or your home’s lights are attracting them in. Reduce the number of miller moths in your garden by removing any unnecessary foliage, tall weeds, grass, leaf litter, etc.
Not only do they bring in moths, but they also attract a lot of other pests that hide feed, and breed in them. Then bigger pests will eat those smaller ones. And then bigger ones will eat the big ones.
Get the point?
If your garden provides a food source for any bugs, you’ll get bugs in there. This just starts the cycle of pest problems in your garden.
Bugs in the yard may seem like no problem, especially to those who don’t care for their garden.
But over time, they’ll slowly find their way into your house for shelter, temperature regulation, or food availability.
Keep your garden clean and maintained. If it’s an absolute disaster, spend a weekend or three cleanings it up. Or hire a gardener to do it for you if you’re busy.
Just like fixing up your house, it pays off over time. It’s another form of natural pest exclusion that’s overlooked.
Dish soap
You can make your own dish soap spray to eliminate these moths.
A mixture of dish soap and water makes an effective DIY moth killer.
Combine a few drops of dish soap into a quart of water and then spray it on any moths you come across to instantly kill them.
Then clean up their bodies without squishing or rubbing them on anything for a clean kill. This makes it easy to catch them since they’re clumsy flyers.
Vacuum
Like vacuuming? Then you’ll love that you can simply vacuum up the moths in your house with the power of a portable vacuum.
Get them easily off the drapes, curtains, or your kitchen counter without smashing them. A handheld vacuum makes the easiest way for quick miller moth eliminations.
Plus, no mess!
Smack them
When you’re trying to enjoy your tomato soup but a miller moth steals the show, smack it!
Use your hand, a shoe, or the traditional role of newspaper to give it your best regards.
Of course, you’ll want to watch out for whatever it’s landing on because it’ll probably leave behind a messy stain for you to clean up.
Don’t kill it if it’s on something like fabric or something hard to clean. The best time to kill a miller moth is when it’s in mid-flight.
Use your hands and give it a good clap. Just make sure whatever you use, watch your promotion, and don’t hit something or someone by accident.
Build a DIY miller moth trap
You can build your own moth trap with basic household materials you probably already have lying around.
All you need are the following:
5-gallon bucket
3 gallons of water
2 tablespoons of dish soap
Waterproof flashlight with batteries (MUST be completely waterproof and submersible)
Here’s how to build it:
First, find a location where miller moths are active inside your house
Get the bucket and pour the water inside it
Pour the dish soap into the water
Swirl gently until it suds
Get the flashlight and place it somewhere above the bucket so the light points into it (such as a chair, stepstool, cardboard box, minifridge, etc.)- You may have to tape it to something to work
Ensure that the flashlight is waterproof in case it falls into the bucket!
Turn the light on and aim the light directly into the bucket of soapy water
Leave it on overnight to catch miller moths passively
How it works:
The miller moths are attracted to the light, so they’ll fly to it
Some will fall into the water in the bucket
Once in the water, the dish soap makes them unable to fly back out
They’ll drown inside the solution
Notes:
You can put this anywhere in your house that’s safe for it
You can build multiple and use them in different rooms
If you have a weatherproof light source rated for outdoor use, you can set up the trap outside in your garden to catch moths
Make sure that the flashlight is 100% waterproof and has a working battery gasket to prevent water insertion
Keep the area clear of people, pets, and anyone/anything else that may knock over the light
Electricity and water never mix!
The light should never be directly over the bucket where it can fall in
Add a noise machine nearby to help make the moths panic
Replace the water as needed
Here’s a good example video:
Natural predators that eat miller moths
The miller moth is a slow flyer and has plenty of natural predators that would gladly gobble them up
When they’re only a caterpillar, they’re extremely vulnerable to enemies like beetles, wasps, birds, rodents, tachinid flies, and reptiles like lizards. Adult miller moths are also vulnerable to flying predators like bats or even frogs and toads.
The larvae are eaten by birds like house sparrows, which hunt them down for their next dinner. If you have any of these native to your garden, consider attracting more of them to help control the population.
There are dedicated species that eat either the cutworm larvae or the adult miller moth. Find out what you have in your garden. And then get more of them.
Set up noise machines (supersonic repellents)
Did you know that sound waves can directly affect the behavior of miller moths? That’s right. Millers are extremely sensitive to sounds.
Whether it comes from you talking to your buddy on the phone or drumming on the wall, it can change their flight pattern. Moths will generally fly away from sounds because it could be related to predatory evasion (they hide from bats that use echolocation).
So if you have any noisemakers, fans, or even those supersonic repellers, consider putting them around your home to naturally repel these insects. If you test it in your room and it works, consider installing them in all your rooms to keep them out for good.
How to get rid of miller moths outside your house
Miller moths outside your house can be found around your porch lights, front door, or in the garden.
They’re probably trying to find a place to rest on their long journey. If your garden provides them with foliage to sleep in plus a source of nectar to feed on, then it’s favoring them.
For outdoor lighting, switch to yellow bulbs. This naturally doesn’t attract insects yet still provides bright lighting. These bulbs may also be called “bug lights.”
There’s nothing special about them and they provide bright lighting just like incandescent bulbs. They just don’t emit light in the wavelength that attracts bugs.
Even though they’re not perfect, they still work to a degree that can offer you light without bringing in swarms of pests.
If they’re always around your doors, seal them with caulk to make sure they can’t get in through damaged frames. You can also use an under-door seal to close the gap so they can’t fly in under your door.
Millers moths that are in your yard may be either resting on the plants, eating them, or you may even have larvae feeding on them.
If you see army cutworms, this is a sign that the adult millers have mated and then chosen your yard to deposit their eggs. Congrats.
You’ll want to quickly prune off any infested foliage. Spray down any larvae with dish soap and remove them manually. Use a bucket full of soapy water to quickly kill the larvae by tossing them in.
Get a till and till the soil to expose the pupa hiding underneath. Dispose of them or let them be visible to birds so they come to eat them.
With basic techniques, you can get rid of miller moths outside your home without the use of chemicals. If they’re migratory, they’re only bound to stay for a few weeks.
But if they’re breeding in your garden, you’ll want to do something about it quickly before they go full swarm.
How to get rid of miller moth eggs
Miller moth eggs are laid on dense plants. If you see them, they’ll look like small clusters of sticky ovals on leaves.
You can prune them off and put them into soapy water to kill them. Keeping your plants pruned and regularly removing weedy or tall grassy plants will help reduce the chance of an infestation.
This is why it’s important to not let your garden go crazy and have wild things growing all over the place.
Not only does it attract moths, but it’ll make your garden into a spawning pool for all sorts of nasty insects. Hire a gardener if you’re too busy to clean it up. Otherwise, spend some time getting it fixed.
Remove plants
Miller moths are attracted to specific nectar-producing flowers that can increase the number of them around your purport. During migrations, they need to feed to sustain their long flight.
They fly at night and will gravitate towards flowers that are yellow or white. That’s because these flowers stand out in the nighttime moonlight.
If you have any of these plants in your garden, you’re probably harboring a bunch of these millers:
Yellow buckeye
Cotoneaster
Rhubarb
Burning bush synonyms
Raspberry
Russian olive
Pea shrub
Cherries
Lilac
Lindens
Source
Pines
Shrubs
Alfalfa is one of their favorite plants to lay eggs in. It provides them ample plant coverage from enemies. It also provides them a steady food source.
If you don’t need any of these plants, remove them. This may help make your home less prone to infestation during its migration period.
They may flock to your neighbor’s garden instead of for a pit stop. Homes that have more flowering plants will attract more miller moths as they need shelter during the daytime. Homes that are also poorly maintained with a bunch of easy entryways also lead to more pests.
But this is true for any garden pest. If your home isn’t properly sealed (pest exclusion), you’re inviting bugs inside. This is why keeping your home in good condition does more than you think for pest control. It’s the number one way to DIY pest exclusion but is often overlooked.
People resort to poisons, insecticides, and pesticides without thinking of fixing up their homes instead. There’s no need for dangerous residues to be sprayed everywhere when you can just do the basic work and patch up your home. This does 10x the effectiveness of pest products.
Combined with natural pest remedies and exclusion techniques, you can make your home a lot less prone to bugs with some basic TLC.
How to get rid of miller moths in your house
Meal moths can eat plastic and paper food packages. If you see them, they’re not miller moths.
They get inside your house by sneaking through tiny crevices and cracks around your property.
They’re tiny, so they can get in through doors, windows, garages, and even smuggled on your clothing.
Miller moths in the house can be controlled by manual removal.
For those that you come across, you can vacuum them up, spray them with dish soap, or set up sticky traps around areas that they frequent. The number one way to prevent them from getting into the house in the first place is pest exclusion.
Once they get in, you can only manually get rid of them as they’re unlikely to find their way back out. Read the previous sections of this guide for more details.
Cars are also a passageway for them as many hide under the hood and then find a path of entry through your garage.
Millers hide during the day as they’re nocturnal, so they come out during the night before daylight. If you find one month, you probably have many others as they travel together.
They come out at night and resume their migration, so you could only see them for a few days before they leave your property until the next batch. Your house was likely a “hotel” for them on their trip.
Sometimes they find their way into your house unintentionally as they’re not the brightest of the bunch. Note that other months are also commonly found in the house and will infest it.
Some of these include the Indian meal moth, which hides in dried fruit, grains, rice, and other dried foods.
It’s easy to get the pantry moth confused with the army moth as they’re both similar in appearance and will be found inside your house. Clothes moths are another home infestation but don’t like Colorado homes because of the lack of moisture in the air.
The chances of army miller moths infesting your home permanently are low. They’re more of a nuisance than temperature and only come out at night. They probably mistakenly found their way into the house. They don’t infest and won’t breed either.
So you’ll likely see them magically disappear within a week.
What about commercial pesticides? Insecticides?
These rarely work to kill these insects. They’re only going to put dangerous rides all over your property and will likely do nothing to impact their populations.
Stick with regular DIY home remedies for best results. There’s no need to spend your money on these products when you can handle it on your own for free or next to nothing. Miller moths are almost invulnerable to most insecticides.
Plus, any moths you do happen to kill will only be a food source for other bugs to eat. You should avoid using any pesticides for miller moths as they’re largely ineffective and are just a waste of money.
Use natural methods and you’ll find that even though they require a bit of work, they actually work.
Miller moths in the pantry
Control meal moths by taking careful steps and purging your pantry.
If you have miller moths in your kitchen, be sure that they’re miller moths.
They could be Indian meal moths, which are confused with them because they look similar. Miller moths won’t eat your kitchen foods and also won’t infest them.
If you see a bunch of moths hiding in your food, laying eggs in them, or larvae crawling around inside food packaging, those aren’t milder moths. Remember that millers don’t infest your home, don’t lay eggs inside, and don’t eat human food.
While miller moths can be a nuisance in their sheer numbers and finding them everywhere, they’re rarely a real threat to your home or garden.
After their annual migration is over, they won’t bother you until next season, or until they do it in reverse.
Since they rarely infest households, you can literally do nothing until they leave and resolve on their own.
But if they’re driving you crazy, a combination of moth traps, repellents, and exclusion will kill and eliminate them. You probably won’t get rid of them completely, but you’ll be able to get them down to a manageable level.
What do you think?
Do you have any specific questions about eradicating, controlling, or managing miller moths? Perhaps you have some tips/tricks to share on handling these insects? Post your comments below and let me know.
Currently an active researcher in the pest control industry for the past 8 years- with a focus on using natural and organic methods to eliminate pest problems.
I share handy DIY pest techniques I come across here to help out others (and possibly save them from a mental breakdown).
