Bat Prevention Tips

If you already have bats in your attic, this page isn't terribly helpful. You can read on my home page that you've got to get the bats out, then seal the entry holes shut. If you don't yet have bats, and just want to know how to keep away bats, then the way to prevent them is pretty simple: just find every possible tiny entry hole and gap leading into your house, and seal the holes shut. Pay particular attention to the roof lines - fascia boards, gable vents, dormer peaks, soffit eave gaps, etc. Any gap of 1/2 to 1 inch is especially desirable. Bats can't chew, so caulk or polyurethane sealant works great!

Living in most any part of the USA, as long as there's fresh water within 50 miles or so, usually means that you will be close to bats. The warmer temperatures make bats more common. If you live in one of these areas it is very probable that at one point a bat will come into your house or property. The best way to prevent that is exclusion. If you don’t take care of bats in one of the buildings on your property, you would see the colony end up being about double the size every year. The good news is that bats do not reproduce as fast as other animals. A female bat will give birth to a single baby after pregnancy. That is also the reason these animals are protected, they reproduce slowly and are very important for maintaining the ecosystem.

Inconveniences Of Having Bats In The House
A lot of people understand the benefits of having bats flying outside their home. However, having them inside is another thing altogether. Bats carry diseases which can be transmitted to humans but that is not the only reason to want them out. They also make noise which can be annoying to a lot of people. They can cause a mess with their droppings which are another way that diseases can be transmitted to humans. Besides the mess there is also a smell associated with guano (bat droppings) that will never be considered pleasant. Finally they can cause damage by chewing through wood, wire or insulation. Their droppings can build up and rot through the floor or roof. In addition, bats can bring in mites, fleas or ticks and these parasites can bring disease as well.

What Not To Do
Once you have bats close to your home there are a few things you may think are a great idea but that in reality are useless and in some cases cruel. Bat traps are useless; they will hardly ever work and even if you were to trap one and release it outside, there is a very good chance that the bat will come right back in. Another thing that you should never try is fumigation. Fumigation is not only cruel but in a lot of areas it is actually illegal. You may be exposing yourself to a fine and the bats that die from the fumigation or poison may go into the walls and decompose there. Repellants are not at all reliable. There have even been warnings issued because some are considered fraudulent products.

How To Find The Entry Points
In order to keep away bats, you will first need to find the openings which the bats are using to get in. These openings are more than likely high on the structure of your home but in some cases a lower entry point which leads to the basement will be used. Go around your home, especially the high places, and look for such entry points. Even if you think the hole is too small, you should seal it with caulk, wood, wire mesh, spray foam, bird netting or steel wool as they will keep the bats out. Make sure you are very observant and that you do not miss any such holes. Be careful using ladders, especially during night time, as a bat may surprise you when it comes out.

Seal Your Home
A bat which has found a way to get in and out of your home will do so freely. They will come back to their shelter and see your home as such. The best thing to do to prevent bat infestation is to keep the bats from getting in. Doors and windows which are unscreened should remain closed, especially during the night hours and at dusk. If you have damaged screens you should repair them as soon as possible. Another thing to do would be to cap the chimneys if you have any. Finally, if you have any holes or openings on your walls or roof you should make sure you close them. A half square inch would be enough for a bat to get in.

Seal-Up Products
My indispensable tool is the Pageris pro sealant gun that you see in these photos. I've become a wizard at controlling the flow, making it look pretty, and most of all, applying it in the right areas. But you can use a variety of products to seal the holes.

  1 - Polyurethane Foam - the Great Stuff in a can that you can buy at Home Depot or Lowe's is a type of this foam. But I use a higher-density product, dispensed from a professional foam gun with flow control. It is also black, which is far less visible than the off-white Great Stuff, which cures to become orange over time! It looks bubbly and ugly. Never use this foam at a time or in an area where bats can come into contact with it before it dries and hardens, or else it will get on the bats and possibly kill them.

  2 - Caulk - regular caulk of many kinds can be used to seal the gaps in a building - an all-weather rubberized kind is best. You can apply it with a regular caulk gun. Caulk only comes in limited quantities, so you may not want to use it if you have a huge job with a lot of volume.

  3 - Steel screening - staple or screw steel screening over gaps. It has to be a fine enough mesh. Quarter inch or even half-inch works. But didn't I say that bats can enter through a half-inch? Well yes, but it has to be a wide enough gap. Bats can flatten out to get through cracks. So a half inch by at least an inch wide, maybe more. 1/2 x 1/2 is too small.

  4 - Netting - in some areas, that 1/4 inch poly netting works great, such as when you have to stuff gaps between barrel tiles on a roof. You can also use crumpled chicken wire, steel wool, etc. Just make sure it's in place.

If The Bats Are Inside The Home
If you want to seal the bats out because they have already made their way inside then you could start the plugging of holes process but make sure you leave at least one exit in case some bats are still inside. If you have already sealed all the entry and exit points and there is a bat inside try opening a window or door and that should lead the bat outside. You are best to use nylon netting for exclusion that will allow the bats out but not back in. If you get bitten by a captured bat, take it to your health care provider or hospital. They will send the bat for testing if necessary to find out if it had any infectious diseases. The summertime is the worst time to do exclusion as baby bats do not fly yet and will remain in the house trapped inside.

Read more articles about bats:
Do mothballs help repel bats?
Fastest way to get rid of bats
What is a bat’s natural habitat?
What is a bat’s natural diet?
Should I relocate a bat?
Is it legal for me to trap a bat?

HELP: If you need professional help in solving your bat problem, please click on my Hiring Advice and 2018 Directory of Bat Removal Professionals serving every city in the USA.

Go back to my main bats in the attic home page for a complete guide on how to keep bats away from the attic or home. Good luck!

Wildlife Education - Information and Advice for the Safe Removal of Bats from Attics