Army cutworm

The army cutworm (Euxoa auxiliaris) is a species of moth. Its nickname "miller moth" comes from the fine scales on its wings that rub off easily and remind people of the dusty flour that covers the clothing of a miller.

Its caterpillars are pests of oat (Avena sativa) and common wheat (Triticum aestivum). The miller moth is a seasonal nuisance in the spring in states including Colorado, Wyoming, New Mexico and Kansas, as they hatch in the low-lying farmlands, then migrate to higher elevations for the summer. They return as the weather cools but in smaller numbers. They are considered nearly impossible to control through normal pest extermination techniques because a new batch shows up every day as they migrate. With their very small bodies, they enter homes (attracted by the light) in the evening through any available crack or crevice (doorjamb, chimney, etc.) and residents in migration paths report dozens of moths per day entering their homes and garages. However, other than being a nuisance, they are not considered harmful.