Spring in the High Plains usually means large numbers of "Miller moths" arriving in homes and businesses. Some years there will be just a few moths and some years there will be hundreds or thousands per night. This year (2014) the flight is fairly light, mostly because we are in the fourth year of severe drought and the larval host plants are either very stressed or not growing at all. Colorado State University has an excellent fact sheet on these insects. Our Miller moths on the High Plains are almost entirely the army cutworm moth. These moths are actually on a long range migration to Colorado and New Mexico. These very same moths will return in the fall and lay eggs on on some of our crop plants like alfalfa and wheat and the resulting larvae will develop over the winter, become adults in the spring and make the return trip to the mountains. It is an astounding feat for a moth to survive eight months and make two flights of 500 miles or more.
There is nothing that can be done when the moths become pests in high numbers, except to keep porch lights off and seal gaps around doors and windows. On the Texas High Plains it usually takes three weeks or so before the seasonal migration ends.