How To Get Rid of Bats in the Attic

When seen up close, bats are almost comically grotesque, and with their helter-skelter flying patterns at dusk, as they search for food, they are the stuff of horror movies. But don’t let appearances fool you into unnecessarily demonizing the ones taking shelter in your attic. “Bats in the attic typically pose very little direct threat to people,” says Meg Pearson, the Training Manager at Critter Control, a pest control service that operates nationwide. “The largest threat comes from the accumulation of bat guano.”

Guano is bat-speak for poop, and as you might suspect, it’s no more hygienic than mouse or rat poop, and it smells far more pungent. By itself, bat guano and urine can spread diseases like leptospirosis, salmonella and histoplasmosis, and they also promote the growth of fungi capable of causing respiratory ailments.

Bats benefit the environment, with each one able to consume 3,000 insects in a single night, but for a homeowner, an ever-growing pile of guano can easily outweigh the benefits. In other words, a bat colony isn’t something you want in the attic, especially if you store stuff there.

If you have a bat infestation and you’re wondering what to do about it, this post has you covered.

What To Do When You Have a Bat Infestation

You should call a wildlife control expert for help. Pearson explains: “Given the potential health threats, as well as laws and regulations (such as bat blackout periods during maternity season) governing removal, it is not recommended that you try to remove bats on your own. If you suspect bats in the attic, call in a licensed professional.”

Considering that not every community has access to competent wildlife control personnel, and in those that do, not every homeowner can afford to hire them, the next best thing is to try to exclude them yourself. Remember that pups are born anywhere from late April to early June, so bat removal cannot occur during the summer because the pups can’t fly yet.

For other times of the year, here are two possible exclusion strategies:

Wait for winter and seal the attic

Bats will hibernate in the winter if the temperature stays around 35 to 40° F. When it gets colder than that, the bats in the attic will migrate out. Once they leave for the season, you can seal up cracks and other entry points to prevent them from returning.

This method gets Pearson’s seal of approval, although she still recommends calling in the pros: “The best way to prevent bats from returning to your attic is to have the area fully sanitized and then sealed off by a pest control professional.” She recommends pros because, as she says, some bat species can fit through a space as small as a dime, so it can be hard to pinpoint their entryways with an untrained eye. The task of sealing small openings probably isn’t beyond the capabilities of a meticulous DIYer with a sharp eye, however.

Install one-way exclusion devices

If you live in an area with mild temperatures throughout the year, the bats will stay year-round. In this case, find the entry points, which are often marked with an accumulation of guano or urine stains, and use exclusion doors and traps to allow the bats to get out but prevent them from getting back in.

• Exclusion screens: One exclusion method involves installing a piece of screen or netting that hangs a foot below the bats’ exit point. You tape the netting along the top and sides but leave the bottom free so the bats can get out but can’t get back in. When the bats are gone, you remove the screens and seal the openings.
• Exclusion cones: Exclusion cones, such as the Bat Cone Excluder, have an opening that bats can squirm through from the inside but can’t enter from the outside. You can mount one using pushpins, staples or duct tape, and most are completely reusable. Mount the excluder with a downward angle for optimal results, and once all the bats are out, remove it and seal the opening.

Be Sure to Clean Up

If you follow Pearson’s advice and hire control specialists, they will remove all the guano, much of which they’ll likely have to scrape away, then they’ll treat the area with an enzymatic stain remover to neutralize the odor. If you don’t hire pros, you’ll have to do all this yourself, so have gloves and a respirator handy.

Don’t skip the clean-up; it’s important for two reasons. The first is for your own protection against lingering pathogens. The second is insurance against the bats returning. Bats tend to return to their previous roosts, which they can find with their excellent sense of smell. Bats can live for as long as 30 years, so if they don’t re-colonize your attic next year, they might find another entry point three years down the road and reappear unless you wipe away all traces of their odors.

What Not To Do When You Have a Bat Infestation

Forget about trying to exterminate bats in your attic. Several bat species are protected under the Endangered Species Act, and even if the ones in your attic aren’t among them, they may be protected by local laws because they help control insects. In any case, you probably don’t want to get close enough to the bats to identify them.

This nullifies what would seem to be the easiest and most obvious way of controlling the bats, which is to poison them. Poisoning bats is expressly prohibited almost everywhere, and even without the prohibitions, it’s a dangerous strategy. It risks the possibility of spreading the poison to bat predators and other wildlife. Not to mention that the last thing anyone needs is an attic full of dead and decomposing bats spreading pathogens and foul smells throughout the house.

About the Expert

• Meg Pearson is a pest control expert and the Training Manager for Critter Control, a nationally franchised pest control service.

Sources

• U.S. Fish & Wildlife Service: Bats are one of the most important misunderstood animals