Miller Moth Migration 2025. The moths are making their migration from colorado’s eastern plains to the mountains. Expected to commence around late may to early june, the miller moth migration in colorado is driven by the moths’ need to find optimal feeding sites and suitable conditions for mating and laying eggs.

Once reviled widely as a nuisance, the millions of miller moths migrating through cities along colorado’s front range this week increasingly are seen as an ecological necessity. The miller moth migration usually takes place in may and june.