What Kind Of Damage Do Bats Cause?

bat damage caused by guano

Bat Damage From Guano

We’re often asked about what kind of damage do bats cause. Bat damage can become significant if bats are allowed to remain in a structure. Bat colonies can range in size from a few bats to thousands of bats. A few bats living in an attic is bad, but can you imagine the problem with having hundreds or thousands of bats living in a structure. The biggest problem to homeowners is the accumulation of bat guano (bat feces) and urine which damages sheet rock, insulation and creates a horrible sickening smell.

Most bat colonies in homes are maternity colonies. Bats living a long time and female bats have 1 – 2 baby bats each birthing season, depending on the particular bat species involved. As new bats are born they add to the continuously growing colony size. As you can see, a few bats living in your home can grow in size to a large bat colony in just a few years. That’s when the problems really begin.

Problems caused by bats in houses range from potential exposure to a rabid bat, parasitic bat bugs (similar to bed bugs), and illness from exposure to potentially harmful bat guano. Exposure from contaminated bat guano can be minor or life threatening. Hearing the occasional squeaking or rustling sounds of bats in your attic, chimney, or walls can be a nuisance, and even a bit unnerving. It can be disturbing to you and your family to find a baby or adult bat in the living areas of your home. If a bat gets trapped and dies somewhere in the walls of your home, you may notice the unpleasant smell of decaying bats. Problems with bats can start as a minor annoyance, but if left unaddressed, will eventually become a larger problems and could end up costing you hundreds if not thousands of dollars.

Damage And Odors
Bats don’t cause the same sort of damage that other critters do. The issues often associated with bats include rabies, bat bugs and possible illness associated with exposure to contaminated bat guano. As the number of bats in your home increases, the strong and foul odor that results from their urine and droppings-called guano, increases as well. If you have a colony of bats living in your home, they are leaving behind urine and droppings on a daily basis. As their excrement accumulates, the odor increases and can become unbelievably overpowering to you and your family. Bat guano also carries a threat to your health that can be fatal in some cases. Bats can also damage your home by damaging insulation, walls and sheetrock.

Bats are a rabies vector species. Rabies, although rare, is spread to humans from a bat bite. Rabies is a virus that causes inflammation of the brain and is fatal if left untreated. Although rabies in bats is typically low, it is impossible to determine if a bat has rabies by its mere appearance. If you are bitten by a bat inside your home, or if you feel that you may have been bitten by a bat, you should notify your doctor right away. There is no cure for rabies.

Bat guano, another issue associated with bats, can contain the fungus histoplasma capsulatam. The spores of this fungus are microscopic and when airborne can easily get into the living areas of your home. When inhaled, the spores of the fungus can cause a disease called histoplasmosis, which usually affects the lungs, but in extreme cases can spread to the major organs of the body leading to death.

What To Do If You Have A Bat Problem
The first step in solving any bat problem is finding out how they are entering your home. Bats can enter very small openings as small as 3/8″ by 1″. Often times, these small openings are undetectable to the untrained eye. To find the entry point, or points, of your home, look for evidence of bat guano or urine on the exterior of your house. If there is a lot of guano on a particular wall or an area of your roof then that is likely where the entry point can be found. The same is true for urine stains; if you see a lot in one area, it is likely that the bats are entering and exiting very near that spot. You can watch your house at dusk and wait for the bats to exit your house on their nightly hunt for food. They will almost always leave as a large group, so if you are looking in the right spot, you won’t miss them.

If you can’t catch them exiting, examine your home closely for areas where the bats may be entering and exiting. You will likely need a tall ladder for this as bats prefer heights where they are safe from predators and they have room to take flight. Bats can squeeze through an opening that is only 3/8 of an inch large, so you must be meticulous in your search. Common entry points are ridge caps, vents, and gaps in eaves and fascia boards. You should also examine thoroughly any areas of your roof or structure that may be damaged, allowing for bat access. This could be a broken window, loose board or piece of siding, or a missing or broken brick.

After locating their entry points, you will need to remove them and bat-proof your home to help keep them out. Once bats have been evicted they will continue to probe your home for openings. If you have not sealed your home properly they WILL find the openings you missed – I guarantee it. Attics are attractive to bats because they offer a warm environment in which to raise their young and are an excellent place for bats to overwinter. If your attic is very warm as most are, or if you live in an area that is warm all year, the bats will never leave, except to go out each night to feed. If you live in an area that is colder during the winter months, the bats may migrate for the winter only to return in the spring when the temperature warms.

It is illegal to fumigate bats or to hurt them in any way. It is also illegal in most states to seal bats out of your home during seasons when there could be flightless baby bats that are dependent on their mothers for survival still on the roost. You need to get the bats out, and you need to seal all entry points, but these things must be done legally and humanely. You can wait until the babies are grown and are flying out nightly, and seal your home then. Usually about 5 – 6 weeks after birth. You can also wait until they migrate to their winter hibernation sites in late Fall or early Winter, and have your home sealed off before they come back in the Spring.

Additional Reading:

Does Homeowners Insurance Cover Bat Removal Costs

What Problems Do Bats Cause When They Live In A Building

Do you need professional help in solving your bat problem? If so, please click on my Directory of Bat Removal Professionals serving every city in the USA.

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