Telltale Signs Of A Bat Infestation

In the wild, bats are very beneficial. The average bat will eat around 1,200 mosquitoes per hour, which can help you enjoy a bug-free night on the patio. Unfortunately, these beneficial flying mammals quickly turn into pests once they enter your home.

Bats will not only cause damage throughout your home, there are carriers of several potentially-fatal diseases, including rabies. Here are a few signs you need to watch out for that could indicate you have a bat infestation in your home.

You See Bats Inside and Entering Your Home

One of the most obvious signs of a bat infestation is seeing a bat flying around your home. However, just because you notice a bat in your home every few years, you shouldn't assume a colony is calling your attic home. Instead, if you see a bat flying around inside you home, head outdoors at dusk or dawn and watch for bats flying inside and outside of your home.

Bats are nocturnal creatures and if they are living inside your attic, you will notice them either leaving as the sun goes down, or entering your home first thing in the morning.

Strange Noises

Another sign of a bat infestation is strange and noticeable noises during the night. For example, bats will make high pitched squealing and whining noises when they communicate. You might mistake the sound for mice or birds, but if you hear it consistently at night, it could be bats in the attic.

Additionally, bats will make noticeable scratching and scraping noises in the walls and attic at night.

Bat Droppings and Urine

The most notice and offensive sign of a bat infestation is the presence of guano, or droppings, and urine. If you find piles of black animal droppings in your attic, your first thought might be a mouse or rat infestation. However, if you notice the guano appears shiny in the light, it is actually bat feces.


The bright flecks in the guano is caused by the thousands of insects a typical bat eats every night. In addition to your attic, piles of bat guano are often found in places called feeding roosts. These include behind your outdoor shutters or on your back porch.

Bats will also create noticeable urine stains anywhere they roost, including areas inside or outside of your home. The urine stains will be white and have a strong odor of ammonia.

If you notice guano piles in your home, do not attempt to clean them yourself and instead, contact a professional. Bats are known carriers of a potentially-fatal disease called histoplasmosis, a fungal infection. When the guano is disturbed, the fungal spores are easily inhaled, and can lead to a host of serious, life threatening complications.

Black Stains Near Entry Points

Finally, watch for black stains on the siding or roofing material where the bat is entering and exiting your home. Bats can squeeze into small spaces, and you might be surprised at how little room they require to enter your home.

For example, if there is damage at the peak of your roof, a bat can easily squeeze between damaged asphalt shingles. Another common place that bats enter a home is through unsecured attic vents. Finding the black stains is actually helpful because it will allow you, and a professional exterminator, to pinpoint where the bats are entering and exiting your home. The consistent temperatures, darkness, and protection of your home and attic is very attractive to bats. If you suspect there is a bat infestation inside your attic, or near your home, don't hesitate to contact the professionals at Craig & Sons Termite & Pest Control, Inc.