Why Are Bats Roosting in My Home? The Reasons Behind Infestation
If you’ve discovered bats roosting in your attic, eaves, walls, or behind shutters, you’re not alone, and you’re probably wondering, “Why my home?” Understanding why bats choose certain structures to live in can help you prevent future issues and decide how to address an active infestation.
Here’s a straightforward explanation of the most common reasons bats take up residence in homes:
1. Shelter From the Elements
Just like humans, bats are looking for a safe, dry, and temperature-controlled place to live. Attics, soffits, rooflines, and wall voids provide the perfect conditions for bats to roost during the day, raise their young, or hibernate. These spaces are:
Dry and protected from wind and rain
Warm during summer and insulated in winter
Undisturbed by human activity
2. Easy Entry Points
Bats don’t need much space to get in—most species can squeeze through openings as small as 3/8 of an inch. Some of the most common access points include:
Gaps in rooflines
Missing or loose soffits and fascia
Vents without screens
Chimneys without proper caps
Cracks near windows or siding
These are often areas you don’t notice until there’s a problem, and bats are excellent at finding the smallest vulnerabilities in a structure.
3. A History of Bat Activity
Once a home has been used as a roost, it’s likely to be reused. Bats are creatures of habit with strong site fidelity, meaning they return to the same places year after year. Even if a bat colony has been gone for some time, the scent markers (pheromones and guano) may remain, acting like a flashing “vacancy” sign to new bats looking for shelter.
4. Proximity to Water and Food
Bats are insectivores, so they tend to live near food sources. If your property is close to bodies of water, marshes, or well-irrigated yards, there’s a good chance it’s also home to large insect populations, such as mosquitoes, moths, beetles etc, which attract bats.
5. Home Construction Type and Condition
Certain construction styles tend to have more problems with bats, especially:
Brick homes with overhanging gables
Log cabins with exposed beams
Older homes with poor sealing or deferred maintenance
Homes with complex rooflines and intersecting pitches
Poor upkeep or original construction design can create unintentional bat entryways. The more little gaps and cracks a home has, the more opportunities bats have to enter.
6. Lack of Human Disturbance
Bats don’t want to be around people, so they typically roost in parts of the home that go unnoticed:
Attics that are rarely accessed
Chimneys that aren’t used often
Wall voids or crawl spaces
Vacation homes that only receive seasonal use
If these areas are quiet and undisturbed, bats may go unnoticed for months or even years, until guano buildup or an accidental sighting brings the problem to your attention.
How to Stop It from Happening Again
If you’ve had a bat infestation, the best course of action is professional bat exclusion—a comprehensive sealing of the entire home that removes bats safely and prevents their return. This includes:
Identifying and sealing all potential entry points
Installing one-way exclusion devices during appropriate removal seasons
Cleaning up guano (if needed)
Performing follow-up checks for new activity annually
Final Thoughts
Bats don’t choose your home because they’re targeting you, they choose it because it feels safe, warm, and easy to enter. Once they’ve found their way in, they’ll likely stay until forced out.
If you suspect bat activity or have noticed signs like droppings, odors, or scratching sounds in the attic, walls, or eaves, it’s worth having a bat professional inspect your property. Left unaddressed, even a small bat problem can turn into a long-term and major issue.