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Where did all these moths in Colorado come from?

miller moth Ben Sale
Ben Sale

COLORADO SPRINGS, Colo. (KRDO) -- It's miller time in Colorado and we aren't talking about the beer. That's right, it's the season of the miller moth.

You may have noticed what seems to be hundreds if not thousands of annoying, dusty-looking moths taking over your homes this May. For native Coloradans, it is something they're used to, but this year seems to be a little worse than usual.

Colorado State University entomology professors Whitney Cranshaw and Frank Peairs say that after four straight years of below-average numbers, this year miller moths, also known as army cutworms, have definitely been in abundance. One of the reasons for that is a dry winter season but a freeze in mid-April that killed many blossoms the miller moths feed on. This forced large populations to congregate in irrigated areas where there are flowering plants.

The report done by Cranshaw and Peairs says the moths are migrating from the eastern plains of Colorado to the west in search of higher elevations like the mountains where they can spend the summer fattening up before migrating back east in September. The professors say the migration period takes between five to six weeks. However, the weather plays a role. On warmer nights miller moths will travel, but during cool and wet periods they are more likely to stay in place.

As for the so-called nuisance period, where you will find them in your house, in between doorways, or flying into your face, that lasts for about two to three weeks.

Both Cranshaw and Peairs say if moths do get stuck inside your home, there is very little damage they can do. They won't lay eggs or feed on household furnishings or food while inside your home. They'll either find a way out or die leading to those massive pileups near windows and doors. These professors say you'll want to clean that up; leaving their bodies can create problems like odor and attracting secondary insects. But they say the biggest issue with miller moths is the lost sleep people get from them flying in their room.

Colorado Outdoors / Colorado Springs / Local News / State & Regional News

Chase Golightly

Chase is a reporter and an anchor for our weekend evening newscasts. Learn more about Chase here.



    1. With the number of moths around, you’re going to need a bigger spray gun… 😁

    2. My cats have been dancing around like clowns and destroying the house in fruitless effect to catch these invaders. My cats make poor predators 🙁

      1. Yes, my kitties too. They even jump on my face while I am sleeping trying to get them. At least they are getting exercise and being entertained.

      2. Mine as well. Though my older one is the only one catching, hobbling and eventually finishing them off. He’s pretty courteous about not wrecking the place, though there have been a few shifted items. =^..^=

  1. “For native Coloradans, it is something they’re used to”
    You don’t have to be a native to be used to the annual miller moth invasion…

  2. Here is an Native trick. Bucket/bowl with soap water in it and place a lamp over it shining on the water. Best miller catcher/killer ever.

  3. They come at night, I use eucalyptus oil, and lemon, for years works great before u go in for night spray around door spray screen..whaa la,you don’t need that much spray u will see them fly like crazy. I keep bowl of soapy water also on my A?C that’s in window UNDER porch light, you wind some in there in morning.

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