bats in our chimney

Asked May 19, 2013, 12:35 PM EDT

We have bats living in our chimney. (We left the flue open—lesson learned.) How do we encourage them to move out without causing them harm? My husband proposes lighting a fire in the evening to smoke them out, after which we will close the flue so they can't return. My concern is that there could be babies that would be stuck inside. Also, there is one dead bat in our fireplace. Should this be examined by experts for the disease that is killing bats on the East Coast?

Benton County Oregon

1 Response

I really appreciate your concern for the bats, and I think you're on the right track for handling the situation. You're right—the bats might have dependent juveniles this time of year, and the last thing you'd want to do is trap the juveniles inside the chimney. To be safe, I suggest waiting until at least mid-August. At that point, any juvenile bats will be independent fliers and will be regularly leaving the roost in the evenings to forage (along with the adults). At that point, it would be good to wait for the bats to depart in the evening, and then cap the chimney with hardware cloth (or a pre-made cap) with openings no larger than 1/2" x 1/2". To avoid needing to do the work in the dark, you could wait until early winter (once the bats have out-migrated) to do the work. Regardless of when you do the capping, it would be great, if possible, to use a light and mirror to check that all bats have vacated the chimney.