Pest Trends
What’s bugging Colorado right now? Our Pest Trends page tracks the pest activity our technicians are seeing in homes and businesses across the Front Range, from Denver and Boulder to Colorado Springs, Loveland, and Greeley.
This week in your region
Seasonal pest issues
Colorado’s dry climate, big temperature swings, and short but intense seasons mean pest pressure can shift quickly: ants and termite swarmers in spring, mosquitoes, ticks, and wasps in summer, and rodents, spiders, and occasional invaders moving indoors as the weather cools. Check back regularly for seasonal outlooks, emerging problems, and public health updates like West Nile virus activity, along with tips on what to watch for and how to stay a step ahead of pests before they become a bigger problem.
Vole populations peak in fall, just before snow gives them cover. Treat now and protect your trees, before they chew bark all winter unseen.
- Weather driver
- Fall breeding peak before snowfall
- Deer Mouse+85%
- Pocket Gopher+25%
- Cottontail Rabbit-10%
Rats are moving indoors as temperatures drop, and a gap the size of a quarter is enough. Seal and treat now, before they nest in your walls and crawl spaces.
- Weather driver
- Cooling nights pushing rats indoors
- House Mouse+140%
- Packrat+60%
- Pocket Gopher+25%
Raccoons are fattening up and searching for warm places to spend the winter. Seal your roof and attic now, before one moves in.
- Weather driver
- Cooling nights and the search for winter dens
- Fox Squirrel+65%
- Striped Skunk+30%
- Red Fox-10%
Pigeon flocks are claiming warm rooftops and ledges for the winter. Bird-proof now, before they settle in and droppings build up.
- Weather driver
- Cooling nights pushing flocks toward warm roosts
- European Starling+90%
- Northern Flicker+35%
- House Sparrow-10%
Mosquitoes are looking for shelter in garages and basements, and West Nile risk lasts until the first hard freeze. Treat now to finish the season protected.
- Weather driver
- Cooling nights driving mosquitoes into shelter
- Culiseta inornata+30%
- Culex tarsalis-45%
- Inland Floodwater Mosquito-70%
Bees in your walls are settling in for winter. Fall is the last window for a safe live removal before cold weather sets in.
- Weather driver
- Cooling days and fading bloom
- Western Yellowjacket+40%
- European Paper Wasp-35%
- Bumble Bee-60%
Earwigs are slipping indoors as nights cool. Seal gaps and treat the foundation before they hide in basements and under doors.
- Weather driver
- Cool nights and fall rains
- Millipede+60%
- House Centipede+20%
- Pillbug-25%
Cooling nights are driving cockroaches into basements and crawl spaces. Seal and treat now, before they settle in for winter.
- Weather driver
- Cooling nights driving roaches indoors
- German Cockroach+25%
- Brown-banded Cockroach+15%
- American Cockroach-30%
Boxelder bugs are swarming sunny walls and slipping inside. Seal and treat now, before they settle into your walls for winter.
- Weather driver
- Cool nights and warm afternoons
- Asian Lady Beetle+80%
- Western Conifer Seed Bug+65%
- Elm Seed Bug-40%
Back-to-school moves and late-summer trips are spreading bed bugs. Get an inspection before they settle in for the winter.
- Weather driver
- College move-ins and late-summer travel
- Bat Bug+50%
- Swallow Bug+40%
- Flea-30%
Bats are looking for warm places to spend the winter. Seal your home now, during the best window of the year for safe exclusion.
- Weather driver
- Cooling nights and fewer insects
- Little Brown Bat-20%
- Hoary Bat-60%
- Mexican Free-tailed Bat-75%
Ants are heading indoors as nights dip below freezing. Treat now before colonies settle into walls and slabs for the winter.
- Weather driver
- Cold nights, warm foundations
- Pavement Ant+41%
- Carpenter Ant-18%
- Field Ant-27%
Male spiders are wandering indoors looking for mates, which is why you’re seeing more of them now. Treat the perimeter before they settle in for winter.
- Weather driver
- Cooling nights and mating season
- Orb Weaver+70%
- Wolf Spider+30%
- Western Black Widow-30%
Yellowjackets get aggressive as their food runs low, swarming trash, patios, and picnics. Treat nests now to finish the season sting-free.
- Weather driver
- Shrinking food supply making colonies aggressive
- Bald-faced Hornet+20%
- European Paper Wasp-35%
- Mud Dauber-55%
Mice are moving indoors as temperatures drop, and a gap the size of a dime is enough. Seal and treat now, before they nest in your walls for winter.
- Weather driver
- First freezes pushing mice indoors
- Deer Mouse+85%
- Norway Rat+30%
- Meadow Vole-15%
Mud-tube and damage reports are climbing. Schedule an inspection before winter slows activity and hides the damage.
- Weather driver
- Warm, wet soil after late storms
- Powderpost Beetle+10%
- Carpenter Ant-18%
- Carpenter Bee-50%
EnviroPest Blog & News
Read the latest articles & news
Why Are Spiders and Earwigs Showing Up Upstairs in Greeley Homes?
Lately, homeowners in and around Greeley have been reaching out after finding spiders and earwigs upstairs. That doesn’t mean the pests are only active on the upper floors—it just happens…
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Why Crickets Are Getting Into Colorado Homes in Late Summer
Hearing more crickets around your Colorado home lately? By late August, cricket activity often becomes more noticeable across the Front Range and Northern Colorado, and it can continue into early…
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Common Summer Pest Problems Along Colorado’s Front Range
Summer across Colorado's Front Range means longer evenings on the patio, weekend hikes, and a whole lot more pest activity in and around your home. If you've noticed ants lining…
Read More