Trying to get rid of bats and they as they are driving you batty? You aren’t alone. There are more than 900 species of these furry flying mammals worldwide, and more than 40 in the United States and Canada alone. These fluffy little invaders love to nest in groups, are attracted to the warm, cave-like, predator-free environments provided by attics, and can get in through holes less than a centimeter wide!

Don’t panic, though.

Bats are not especially destructive, and can even be a boon to gardeners. (Once you get them out of the house that is.) If you want to evict them however, here are some reasons why it’s good to get rid of them, plus some tried-and-true ways to exclude bats from your home, without putting yourself or them in danger.

Why You Should Get Them Out of Your Home

Most bat infestations are fairly small-scale, but that doesn’t mean you should just ignore them. Bats are nocturnal insectivores, that eat a lot of bugs, and therefore produce an equally large amount of guano (bat poop). Guano that is now carpeting your attic. In addition to smelling bad, bat droppings can facilitate the growth of a fungus that leads to histoplasmosis, an airborne infection that primarily affects the respiratory system.

In most cases, histoplasmosis either goes away on its own or is easily treated with antifungal medication, but in the most severe cases (particularly when contracted by infants or those with severely compromised immune systems), the infection can lead to severe complications, or even be fatal, if left untreated. If you fear a bat issue, you might want bats removed by a professional wildlife removal company.

So now that you are armed with intel as to why you need to get rid of them, you’re probably itching to get to it. But wait, there is one more important detail you need to be made aware of.

You Can’t Just Get Rid of Them Any Old Time You Please

Another important thing to know is that bat colonies can only be dealt with at certain times of the year. Due to the crucial environmental niche they occupy, their relatively slow reproductive cycles, and the severe devastation many wild bat colonies are undergoing thanks to a little-understood disease known as the white-nose fungus (harmless to humans, but with a 90%+ mortality rate in bats), it is illegal almost everywhere in North America to intentionally poison or kill bats.

This means that colonies cannot be evicted during the crucial birthing months from May through August, when expulsion of the mature bats would leave the flightless infants to die. Though it isn’t illegal, they really shouldn’t be expelled during the heart of winter either, when the freezing air and (potential) lack of alternative shelter could condemn many of the tiny flying mice to death at the hands of Mother Nature.

How to Bat-Proof Your Home

So, it’s early fall or spring and you’re ready to take back your attic from the bats. Here’s how you do it – it’s relatively easy, and requires nothing that cannot be easily and economically acquired at your local hardware store.

It is, however, important to be thorough. The half-measures recommended by some websites, such as ultrasonic pest repelling devices, high-frequency noisemakers, or naphthalene crystals, tend to be both wildly expensive and completely ineffective. Don’t waste your time or money – just skip to the ways that work.

Go ahead and put a headlamp on your shopping list now. Their favourite place in your house is the dark attic. And the best time to bat-proof your attic is when the bats aren’t there (obviously). Because bats hunt at night, that means you’re going attic-spelunking in the dark.

The headlamp can make it easier to spot small cracks and entryways that would be invisible in the daylight. And because bats are excellent at squeezing through tiny little holes, the more of those you can patch, the more bat-proof your attic will be.

First, you need to seal up the majority – but not all – of the bats’ entryways. Gaps between the roof and the walls, cracks in the siding, and small openings where wires and pipes penetrate the ceiling below the attic all need to be closed. Get up there with your handy-dandy new headlamp, stainless steel wool, and some caulk and start closing up those passageways. Bats don’t gnaw or scratch, so once you close up the corridor, it should stay closed.

That said, make sure you leave a few of the – ideally better travelled – openings for now. You don’t want to accidentally trap the bats inside. If you find any openings that seem to have larger than normal deposits of guano around them, these are probably the most popular entries and exits. Note their location and leave them alone.

Now go check out the outside of the house. (You can do this step in the daylight.) Find the passages you left open the night before, and cover the openings with 12-inch (30 cm) squares of heavy, fine-mesh netting. Make sure the netting hangs freely, creating a one-way exit door for your little bat buddies. Leave them like this for a couple of days, until you are sure that all the bats are gone, and then seal them up too.

The Good News

Congratulations, your house is now bat-free! A quick attic clean up (wearing gloves and a mask, please), and your home is back to its normal, quiet, non-stinky self.

How to Coexist Peacefully with Bats

If you find yourself missing your fuzzy little friends, or at least missing the reduced mosquito population that comes along with them, why not build a bat house for them instead?

The best bat houses are composed of roosting chambers between ½” and 1” wide (2-3 cm), horizontally grooved wooden walls, and black, heat-retaining tarpaper mounted over the roof to keep the bats toasty warm.

Mount the house against an exterior wall with an eastern or northeastern exposure, a minimum of ten feet (3 m) off the ground, and away from large trees that provide concealment for potential predators. A catch-pan mounted just below will keep droppings off the lawn.

Now you can feel good, knowing you’re doing your part to help sustain the vitally important, dwindling bat population, without having to give over your house to the fluffy little buggers.