When Can Bats Be Removed From an Illinois Attic?

Why timing is the whole question

During the summer maternity season, female bats gather to raise young that cannot yet fly. If you exclude the colony then, the adults leave but the flightless pups are sealed inside, where they die — an inhumane outcome that also creates a serious odor and contamination problem in the attic.

That is why bat work is scheduled around the maternity window rather than done on demand. Exclusion is appropriate before the pups are born or after they are flying.

How bat exclusion works

Exclusion uses one-way devices installed at the roost entries that let bats fly out to feed but prevent them from getting back in. Once the colony has left over a few nights, the entries are sealed permanently. It is the humane, protected-species-compliant method — not trapping, poisoning or extermination, which are not appropriate for bats.

What if a single bat gets into the living space?

A lone bat in a room is handled separately and promptly, especially if it was where someone was sleeping, because of rabies-exposure concerns. The bat may need to be captured for testing rather than released. A single indoor bat often also means a roost in the attic, so an inspection checks for a colony to plan exclusion.

Plan ahead

Because the timing window is limited, a bat problem is best assessed early so exclusion can be scheduled for the right part of the season. Guano cleanup follows once the bats are out — handled with proper containment and protection, since accumulated guano can harbor a fungus associated with respiratory illness.