What to do with chimney invaders
How to remove bats and birds that decide to make your home their home
A how-to guru advises readers on the best way to remove bats (or even birds) from a chimney, as well as which kind of light bulb can ward off pesky insects and such from your porch.
Q A new neighbour has bats in the chimney. How do we find someone to remove them? A First, your neighbour should make sure they’re really bats. Although bats occasionally roost in old chimneys, it’s rare for them to locate in modern ones, said John Simpkins, one of the owners of Mid-Atlantic Wildlife Control. “Ninety-nine per cent of people who say they have bats in chimneys have chimney swifts,” he said.
How to tell if it’s bats or birds? Go outside at dusk and watch the flight direction. Bats head out at dusk to feed, while chimney swifts head in to roost.
If the creatures are chimney swifts, just wait a few weeks and they will leave on their own. Chimney swifts migrate to South America for the winter and don’t return until April. By then, your neighbour can have the chimney capped — or look forward to hosting these intriguing birds again. Chimney swifts are never around during fireplace season, so having the chimney cleaned in the fall eliminates the risk that the nests will block airflow. The babies do chatter as they beg their parents for food, with sound level highest during the last two weeks before they fly from the nest. But in return for putting up with that, anyone who hosts these birds gets great insect control and a close-up look at a fascinating species.
“These fantastic flyers do almost everything on the wing — eat, drink, break off twigs for their nests and are even thought to copulate in flight,” the Maryland Department of Natural Resources says on a website page devoted to chimney swifts. The birds are protected by the Migratory Bird Treaty Act in the U.S. (or the Migratory Birds Convention, as it’s known in Canada). A federal permit is needed to remove chimney swifts and their nests during the nesting season.
If your neighbour is dealing with bats, it might also be wise to wait a bit before trying to get them out because babies might still be inside. The only recommended way to exclude bats is to seal all entrances except one and then install a one-way door there so that once bats fly out, they can’t get back in. To avoid trapping babies that are too young to fly out, the Maryland Department of Natural Resources recommends waiting at least until September to install the one-way door.
Bats hibernate beginning in November, so exclusion shouldn’t be done after that, for fear of trapping adults inside. It’s critical not to trap bats inside. If the trapped bats are adults, there’s more chance they will wind up in living space as they try to escape. And if adult or infant bats die inside, the house will stink.
Bat exclusion can range from several hundred dollars to thousands, depending on the size and style of the building and the difficulty of sealing entrances, Simpkins said. (Check with local companies that specialize in bat removal, as prices can vary.)
As part of any bat-exclusion project, the department recommends installing a bat house outside. This will protect the bats, which have declined by about 80 per cent since the white-nose syndrome disease emerged in 2007.