You hear a little squeak in the wall and think it is a mouse. This is followed by a rapid sort of fluttering and more high-pitched noises. You do a little research and realize this is no mouse: you have a bat stuck in your wall. Most people will not find a bat in their home out of nowhere. They typically live in colonies and only enter a house where they have established a roosting spot. Knowing how to get rid of bats in walls isn’t easy, but with a few simple steps you can be well on your way to making your home bat-free once again.
There are a few reasons bats may have suddenly taken up residence in your walls:
- You have a home with lots of outside cracks and holes over a half inch wide that lead to your wall spaces
- You already have bats in your attic or garage and have recently attempted to exclude them and seal off any entrances
- You have an unaddressed bat colony in another part of your home and they are outgrowing their original roosting spot
- A local bat colony was expelled from a nearby location and are treating your house as an emergency roosting spot
None of these scenarios is good, and some bat problems are worse than others. They all, however, require a similar approach to expelling the bats and ensuring they cannot re-enter your walls.
If You’ve Never Had a Bat Problem Before…
If this is the first you’ve seen, or heard, of bats in your house, you need to start the exclusion process to get rid of the bats as soon as possible. Unfortunately, this cannot be done at every time of year. In the case of bat varieties that hibernate in the winter, you may have to wait until they leave on their own in late fall. Other kinds of bats can only be evicted in the time between the time they birth their young and the new bats are big enough to feed with the colony, usually in early fall. Penn State has some great advice on how to determine the timing of your efforts.
You will need to find out how the bats are entering your house and begin sealing up any cracks or holes that could be serving as secondary entrances and exits. You can only seal up the primary hole the bats use once these other spaces are thoroughly sealed and the bat colony has been evacuated from the walls.
If This is Part of An Ongoing Bat Problem…
Anyone who already has bats in another part of the house then finds them in the walls is dealing with a secondary symptom of an ongoing bat infestation. If you have recently attempted to get the bats out of another part of your house, there may have been bats left inside when you sealed up their openings. Their journey down the walls could be an attempt to escape. This Old House features a narrative on how to properly exclude bats from your home. If it is to the point where they have moved from your attic to your walls, however, you might be facing a situation where professionals needs to be brought in to seal off all potential secondary exits before attempting another exclusion.
Another possibility is a bat population overflowing from their original roosting spot. Each female bat has a single offspring each year, growing the colony exponentially over a year or two. The bats in your house might be moving into the walls looking for extra room to live. If you can access the wall interior and see piles of guano you have found evidence they are not just moving through but living in your walls.
Excluding Bats From Your House
Exclusion is the term for the process of making bats leave. Exterminating bats is not practical and is usually illegal. An exclusion requires you to wait until all bats leave then seal up the holes they use to enter and leave your house. According to the Internet Center for Wildlife Damage Management, bats can enter a home through any typical opening in your siding. Some spaces bats use are so small it can be impossible for anyone other than an expert to identify.
Once you have effectively emptied your house of bats, you can take extra preventative measures to make sure they do not show up in your walls again. Keeping your house well-sealed and re-inspecting your house frequently is one step to take; you may even consider installing bat houses on your property to offer a stubborn bat population another place to live.