It's miller moth season in Colorado: Here's everything you need to know about the harmless and important bugs

You've probably noticed them in your doorway, along windows and in the nooks and crannies of your car. It's miller moth season, the time of year when the moths migrate across the state and seem to show up everywhere. 

The moths hatch in eastern Colorado, as well as parts of Wyoming, Nebraska, Kansas and Oklahoma. Then as flowers start to bloom and the weather warms up, they move towards the mountains and the native flowers there. 

"They want to go up to the mountains, reproduce, then migrate back and lay their eggs," said Francisco Garcia Bulle Bueno, an entomologist at the Butterfly Pavilion. "They're just basically living their lives and they're just trying to get some food around." 

Along that journey, the moths must first pass through the Denver metro area. They're often drawn to dark rooms and crevasses during the day and lights at night. 

"We recommend you turn off your lights in the evening and try to keep your lights as low as possible, so you don't get a lot of moths," Bulle Bueno said.  

The moths are critical to the ecosystem as both a food source and pollinator, according to Bulle Bueno, although most associate that role with honeybees and butterflies.

"They're not as charismatic as butterflies in way of very shiny and bright colors, but they are equally as important as butterflies because they are pollinating," he said.

For that reason, experts say miller moths should be protected, not treated as a nuisance.

"If we care about the environment, and a good environment for our kids, grandkids, etc., we need to start protecting insects," he said. "Help move them around, and they're just going to leave us around in a few weeks' time."

Miller moth season typically starts in May and goes into early June. There is a reverse migration in the fall that's usually smaller and less noticeable.