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So how do I bat Proof My home?
I get asked this question all the time, “is bat proofing something that a homeowner can do.” The answer is maybe. Can you work high up on a ladder? Do you have all the equipment to work safely on your roof? Most people aren’t thorough enough to do the job, they will seal up where they see the bats coming and going but won’t seal up the other two dozen spots that the bats are using. Most homeowners will go down to the hardware store and buying 6 tubes of the cheapest caulking they can find or worse yet a can of great stuff and start sealing. At NBWC we use between 2-25 cases of the best caulking to complete a bat job. All places that mice or other rodent can chew through we use galvanized hardware cloth.  If you have roof vents
that the bats can get into we will install roof vent baskets. If your masonry chimney needs to be tuck pointed, we can do that. If your chimney doesn’t have a cap, we will install one. After we correct all the flaws in the home we will install our exclusion valves to let the bat out. 

How do I make and exclusion valve (bat valve)?
A bat valve is a simple device that lets the bats out but they can’t get back in. Every bat valve is custom made for each application. Some bat proofers will use netting put over the holes so the bats can crawl out under the netting but not back in, some will use one way devices installed on the home. NBWC uses both methods. Every Bat excluder is custom made for the flaw the bats are using.

What will happen if I kill the bats by seal them in?
You would not believe how many times I’m asked this question, bat are protected in Minnesota and other states. Most people with bats first discover that they have bats because they are getting into their home. If you try to seal them in, three things can happen.

1) They die and you have successfully killed a protected species.
2) They die and now you have a smell in your wall, we call this type of work search and destroy. We break through the wall board and plaster looking for the mystery smells. It usually runs 4-10 times more as bat proofing would have.
3) They find there way out usually through the living area.

I just re-roofed and re-sided and now I have bats. Why?
Sometimes just by having your home worked on has created new flaws that the bats can now get into. In Minnesota we have codes on how many layer of shingles we can put on a home before we have to tear it all off and start new. So the roofers tore off 2 layers of shingles and put on a new layer. You now have gaps where your soffit meets the new roof.  Or the roofers re-shingled and told you didn’t need a new drip edge.

WRONG, you now have a gap around your entire home that bats, squirrels, or other rodents can get in. Putting on the cheap roof vent on can also let the critters in. When you have your home re-roof make sure they only install bird-proof roof vent. If you are putting on the new style ridge vent system (cobra vents or other brands) have your roofer install a narrow piece of hardware cloth before they install the vents. Yes doing these things will cost a little more money, but by not doing them it can cost you a lot more.

Can I spray some sort of pesticide or use other deterrents to get rid of my bats?
All pesticides are registered by the USDA, and we have no USDA registered pesticides or deterrents for bats. The only way to get rid of a bat colony is to correct the flaws in the structure and evict the bats with an exclusion device. Do moth balls work? All studies have shown that they have no effect on bats or any other rodent.  I have seen hundreds of pounds of moth balls put into attics and the only thing that they keep out is ME.( I don’t like the smell)

The other thing with moth balls is they have a flash point where they evaporate and become flammable. NOT A GOOD THING FOR HOT ATTICS.
If I install a bat house will my bats move to it?
We have 7 different species of bats in Minnesota; they are broken into 2 different categories, Tree bats and Cave bats. Tree bats migrate every winter to warmer climates, tree bats live in trees not homes. Cave bats hibernate in Minnesota and need supplemental heat to survive our Minnesota winters, cave bats live in homes and other heated structures. So in Minnesota a bat house is a temporary structure. I always tell people why would a bat live in a motel 6 when they have a nice home like yours to live in. Bats have adapted and a home has supplemental heat loss and cooling loss, it has no predators to bother them. Some of the old data said that if you have bats to bat proof your home in the winter after the bats leave. WRONG, the bats have never left; they just found a warm spot in your home to hibernate. Minnesota has very few caves left for bats to hibernate in, so they have found something better.
I get an occasional bat in my home in the winter, what does this mean?
It means only one thing that you have a colony of bats living in your home. Bats need a temperature variance of between 32- 49 degrees to hibernate. When we hit -30 it is too cold for the bats to hibernate and they wake up and move to a warmer spot (usually your basement), when it gets +50 I have seen the bats laying on the snow on roofs to stay cool. The bats need to hibernate to conserve energy to survive our long winter. When we have winters with very fluctuating temperatures we have a lot of bats that don’t survive and die. I do a lot of searching for dead animals (smells in your home) in the spring thaw. The same thing happens during our warm summers, the attics get too hot for anything to survive so they move to a place that is cooler.

I have bats roosting in my entry way, does this mean I have a colony, is there anything I can do?
Having bats in your entry way can be a nuisance. You can try some deterrents to stop the roosting. What we do at NBWC is to hang a clear sheet of 4 mil plastic from the soffits down the wall at least 1 foot; we attach the plastic with clear silicone. This keeps the bats from roosting in this spot, it may move them to another spot and you will have to repeat the process.
Having a bat roost doesn’t mean you have a colony in your home. If you enter your attic and find bat guano in your insulation or you have a spot on your siding that is covered with bat guano, I’d be concerned and call NBWC.
I get an occasional bat in the summer time should I be concerned?
Yes, you should. I hear the same story at least 5 times a week, where someone has bat in their living area and they rationalize how it got in the home “I left the garage door open last night and it must have come in the door” or “I was bringing the groceries in last night the bat has must have come in then” Most people believe this rationalizing for a few years then they realize that they have a bat problem. When I inspect a home that has had a bat in the living area about 95% of the time they have a colony living in the home.

Call 763-227-9888 to schedule an inspection