How to Bat Proof a House

Unlike squirrels and raccoons, bats don’t force their way into our homes.

So how do they get in?

They get in through small openings that come to exist on our homes through age, damage, design, or poor workmanship. Or, more than likely, a combination of these factors.

The small stature of Ohio’s bats is one of their biggest assets when it comes to finding shelter.

Little openings that don’t look like much to the untrained eye often lead to nooks and crannies (or big attics) that have climates bats thrive in. If they find the right conditions, they’ll be back year after year.

So, bats happen. And the guano build up…and the urine staining…and an occasional foray into the living quarters…you get the idea.

What next?

Solutions for a Bat Problem

Solving a bat problem, in theory, a simple two-step process:

Make sure all the bats are out of a structure
Seal up the structure up so the bats can’t get back in

But, obviously, this is one of those things that is easier said than done.

Making sure all the bats are out of a house is a process of putting barriers over entrances that let them out, but prevent them from getting back in. How is that done? Great question, but not one we’re going to address today. Instead, please re-read this post to find out we make sure all of the bats are out of of structure.

Bat Cone in Action: Step 1 of Bat Proofing

Step 2, sealing up the structure, is what we refer to as bat-proofing.

Bat Proofing a Home

For bat-proofing, the bats’ main entrances and points of use need modification so that the bats can’t enter or use that spot again. Additionally, once the bats get kicked out they are going to want to get back in. They’ll explore the structure searching for other ways in. This means the whole structure needs addressed: all the potential points of bat entry/bat use have to be included in the plan.

So, the extent of the job depends upon how many potential areas of use need modified.

The modifications to the structure typically include:

Screening- Sometimes bats access vents that are necessary. Properly installed screens with fine mesh prevent bats from getting into openings that have to stay.
Siding, soffit, flashing, and fascia repair- Bats often get into attics through roofing/siding elements that are old, damaged, or installed improperly. Sometimes the best way to bat-proof is to replace the piece that is letting the bats in.
Caulking/Sealing- Often times, a good portion of bat-proofing is devoted to filling in small gaps that exist in building pieces without replacing them entirely. This is accomplished through sealing the existing gaps with filler material and a high quality caulk.

For example, in the following videos you can get a good idea of what bat proofing entails.

The job takes place at a large, log home. Bats were living in lots of little nooks and crannies that were left by the builders. They were also entering the living quarters through multiple gaps left along the roof line. (Proper sealing when it was built seems to have been neglected.)

After the bats were removed and sealed out of the living space, all the other places where they were roosting were modified with a lot of tedious filling and caulking.

The filling is simple foam backer rod easily found at a hardware store. Not familair with it? Google “backer rod” , “pre-caulking filler rope”, or “caulk saver” and you’ll find pictures of it. It comes in different diameters so you simply match the gap to be filled with the right size backer rod.

The sealant which covers the backer and completes the job needs to be a very high quality product. We recommend either SolarSeal #900 or Titebond WeatherMaster sealant. These are specialty sealants for exteriors and are a must.

Towards the end of the video, Ryan also flushes out quite a few roosting bats from the area he intends to seal up.

Besides the roof line, other parts of the home needed sealing. Here Ryan roosts out more bats and you can really see the types of openings that need filled wherever they exist.