People along the Front Range know that this year is a special one for the animals we call “miller moths” – technically the adult stage of the larval army cutworm. Every spring, they arrive en masse from Nebraska, where their larval stage spent the spring in winter wheat and alfalfa fields. They migrate from east to west, into the mountainous areas of Colorado, Wyoming, and Montana. In the daylight hours, they seek shelter, hiding in small cracks and dark crevices – such as your closets or the inner pockets of your car doors. At night, they feast on nectar from flowering plants. The speed with which they migrate depends on the weather – so in a cool, wet spring like we are currently experiencing, the moths will stick around in the lower elevations for a while before migrating up into the mountains where they spend their summer.
In the mountains, they eat wildflower nectar and provide a protein source for bears who are foraging in alpine meadows (whereas in my house, they’ve been providing a protein source for cats and dog foraging in the domestic environment). In September, they migrate east again, arriving in Nebraska in early autumn, where they mate and lay eggs in the same fields that they once sprang from themselves.
Their migration this year has been so big that they even showed up on local weather radar in the Denver area.
These moths also LOVE light. If you have a light on in your house in the spring, chances are a moth will somehow get inside – they are very good at sneaking through tiny spaces – and start flying frantically around it. As the University of Nebraska’s website put it, “Moths inside structures can cause human anxiety from their persistent movement around lighting.” This is a slight understatement for many people, but the good news is that these moths won’t cause any harm to your clothes or your house – they don’t lay eggs here and they don’t eat anything but nectar. They can feel a little creepy when they brush against your skin but unlike many party guests, if you turn out the lights, they will immediately leave.
I chose to draw a moth in a way I often see them, silhouetted against a screen door as it tries to get inside for the light. You can read a lot more about them from Colorado State University.
By the way, I started a new newsletter called Domesticated Species which is about the plants and animals that we eat. This is mainly a way for me to get better at growing my garden but I hope you enjoy reading along too if it’s a topic that interests you. The first post, Broccoli, is here.