Ask the Expert: Bats in the attic? Here’s what to do.

We thought our home inspector had been very thorough. But not long after purchasing our 1868 Mansard Victorian, my wife and I discovered the home inspector had missed something: several thousand bats that live in our narrow eaves! In the summer as the attic heated up, the bats began to show up in the finished rooms on the third floor and stairwell. What should we do?

Going Batty in Vermont


While I’ve certainly run into my share of rodents—flying or otherwise—in my years of renovating houses, I’ve never encountered your predicament, which resembles a Stephen King novel. It must be quite impressive at dusk when they all take flight. My guess is that you don’t have much of a mosquito problem!


Seriously, though, I advise against a DIY attempt. Exposure to bat guano is unhealthy, and there must be heaps upstairs. Don’t just trot up there with shovel in hand and some yard bags; bat droppings can contain a fungus that causes histoplasmosis, and thus it’s time for the hazmat suit and HEPA filter-mask. A diluted chlorine solution is also necessary to neutralize the area. You’re going to need the services of a professional who specializes in bats.

And then there’s persuading the bats to leave—another reason to call a professional with experience. One method involves sealing the roof and eaves of any possible means of egress for the little critters and then creating a portal-like vent tunnel that has a flap on it to prevent re-entry. Come nightfall, the bats will romp around the neighborhood and return, only to find that they’re not welcome. Be prepared for an unexpected scenario: Your suddenly displaced pets may need a little time to understand their eviction notice. They’ll likely hang off of your home’s gutters and soffits before they finally leave in search of a barn, cave or bat house.


But the thought of thousands of bats draped all over a Mansard roof sounds very Gothic; wait until after Halloween before you send them on their way!


• When sealing a house off from any rodent, remember that they only need a hole the size of a quarter to slip through. Cracks in the foundation or between the chimney and siding are favorite entrances.


• Don’t touch bat waste. Regard it as hazardous material and call in the professionals.


• To deter bats, hang strips of aluminum foil in areas that might be attractive to them, such as the junction of the soffit and fascia.


• Remember: Bats are our friends; they are pollinators as well as eat thousands of insects. Plus, they look really cool in flight. Consider building bat houses for your yard or purchasing one ready-made.


• As with any home project, don’t reachbeyond your skill set. (Are you listening, all of you weekend lumberjacks?) It’s not an admission of weakness to call in a pro;discretion is the better part of valor.




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