The terms "miller" and "moth" are basically interchangeable, as a "miller moth" refers to any kind of moth that abundantly appears in and around people's homes, but "moth" can be used as a blanket term for many other kinds of moths. One of the most well-known miller moths is located in Colorado as well as other adjacent states, and is the adult stage of an army cutworm.
These moths are known to be pests because prior to turning into moths, their caterpillar forms will feed on plants, destroying alfalfa and winter wheat. After metamorphosis, these miller moths feed on nectar throughout the early fall, refraining from laying any eggs during this time, a reproductive stage referred to as diapause. As the warmer months approach, they begin to elevate to find flowering plants and have been known to migrate great distances, some as long as 100 miles, in search of summer feeding areas.
They have a wingspan of 1.5 to 2 inches, and their wings are covered in both wavy and dark markings. With their gray, light brown color, miller moths can have many different designs on their wings, but they can all be identified by kidney-shaped markings located on their forewings.