Colorado Bats Have Begun Seasonal Migration
As bats exit attics for winter hibernation, homeowners should take steps to seal their structures against future roosting.
Updated on Oct. 5, 2026 in Wildlife
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Colorado bats have begun transitioning from summer roosts in residential attics and chimneys to winter hibernation sites in rock crevices. This autumn shift creates a brief, optimal window for homeowners to humanely exclude bats from their property.
Why it matters
Securing these entry points now prevents bats from returning to inhabit structural voids like chimney chases next summer. Timing these repairs during the natural autumn migration ensures that no animals remain trapped inside the home.
Colorado Parks and Wildlife notes that bats currently move from summer attic and chimney roosts to winter hibernation sites. Residents are advised to use one-way exit devices during this period to ensure all animals have left the structure before permanent sealing begins.
The players
Colorado Parks and Wildlife
The state agency responsible for managing wildlife populations and providing guidance on human-wildlife coexistence.
The details
Homeowners can install one-way coverings over identified roosting exit points to allow bats to leave for winter hibernation while preventing them from returning. Once the bats have vacated their summer home, all openings must be permanently sealed using caulk or other appropriate materials. Because these repairs involve structural access points, residents should contact a licensed professional for safe, code-compliant sealing work.
Timeline
Summer: Bats typically occupy residential attics and chimney chases.
Autumn 2026: Bats transition to their winter hibernation sites.
The Home Front
Wildlife exclusion follows state-managed seasonal protocols that align with natural migration patterns rather than calendar-year maintenance schedules. These habits are essential for maintaining structural integrity while adhering to state-level animal welfare regulations.
Check your attic vents and chimney chases now for signs of bat activity or guano, which may indicate a summer roost. If you identify a roost, work with a licensed professional to install a one-way exclusion device while the bats are naturally migrating to their winter sites.
The takeaway
The autumn transition is the only time to seal entry points to ensure you do not inadvertently trap bats inside your home. Once the migration is complete, hire a licensed professional to inspect for potential entry points and permanently seal gaps that could invite future colonies.
Further reading
Learn more about managing animals around your property in our Wildlife section.
Source note: This article includes information reported by FOX21 News.
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