Miller Moths Description

There are a dizzying amount of facts to keep straight when it comes to miller moths. Myths and hearsay mix with facts about similar pests and before you know it, you’re bombing your whole house with insecticide that, will have minimal to no effect on a Colorado miller, which starts its life as an army cutworm.

Since miller moths avoid daylight (but they are attracted to some artificial lights at night), you may find some in your kitchen cupboards or pantry. But millers aren’t what is considered a pantry moth. Those are usually Indian meal moths that found their way into your home as eggs in packages of bird seed, cereals and grains, and meals and flours. You’ll often see small larvae with pantry moths, but not miller moths.

Miller moths usually sneak in homes through a crack in a door or window frame, a hole in a screen and other small openings that allow them to shelter from daylight. The millers frequently shelter together, which is why several can make their way into your home at once.

Millers lay eggs in dense vegetation or weeds sprouted in wheat or alfalfa fields (another reason they are confused with Indian meal moths) in late summer/early fall. The army cutworm emerges and begins feeding on nearby grain crops. After wintering over, the cutworm begins feeding again in the spring. The most damage an army cutworm can do is at this time.

In mid-spring, the army cutworms work their way into the soil to pupate. Less than a month later, the miller moth emerges and literally heads for the hills – higher elevation – to feed on nectar. They then return home to reproduce and lay eggs.

The migrating millers can be annoying, especially if they make their way indoors, but they do not eat human food or clothing while indoors. They don’t bite and they aren’t poisonous, but because they are often mistaken for Indian meal moths, few people want them as temporary boarders.

Many natural enemies – birds, ground beetles, flies, wasps and bats – effectively control the army cutworm and miller moth population, Insecticides have little to no effect on miller moths, but they are easily controlled if they make it inside.

Swatting or vacuuming the moths is a quick way to handle them. Vacuum bags should be emptied frequently because the moth carcasses can emit an unpleasant odor. Placing a bowl of water (with or without dish soap) under a bright light is another popular disposal method. Even though the moths don’t like daylight, they are attracted to lights at night and will fall into the water and die.

Prevention is a way to avoid the moths entirely. Check for and seal cracks around your house. Switch white bulbs to yellow (similar to daylight so the moths are less attracted to them) or leave off lights at night.

Millers cause very little damage if they are in your house, but they are pests nonetheless. With a little effort before invasion or a little work after, the moths’ stay can be short lived.