Pest control professionals look for signs of bats in the house or attic to verify the presence of a bat infestation. Bats in the attic are readily identified by sight, sound, and smell, and must be dealt with carefully.
Identification by Sight
Bats can enter a house through openings as small as 3/8 an inch in diameter. Prime spots are usually along the roofline. They will leave brown spots near these openings from the oils in their coats as they crawl into the house. Bats come out at dusk, and this is a good time to spot them exiting the house.
Identification by Sound
Large bat colonies can be heard from an attic. Bat colonies can be quite large as they usually double in size each year. They can stay in warm attics all year long. They are quiet animals, but in large groups they can be heard flying and squeaking. Listen for them at dusk when they are most active. Baby bats will often crawl into walls and get stuck, making noise.
Identifying by Smell
Another way to identify bat infestation in the attic is by smell. Bat droppings, called guano, can accumulate in an attic, producing a distinct smell. This smell is evidence of an infestation. Guano is similar to mouse droppings, except it accumulates in piles below roosts, and is shiny and speckled and crumbles when touched. Bat guano can be dangerous and can cause an infection known as Histoplasmosis, whose symptoms include fever and lung infection. Wearing a HEPA filter mask is suggested when investigating bat droppings. One way to identify an infestation is to lay down newspaper in your attic to see if new droppings accumulate.
Steps for Removal from Attic
Attic bat infestations are very complicated to eradicate. It is best to hire a professional to fix the problem; but, there are steps a homeowner can take. To solve an attic bat infestation, it is necessary to identify the type of bat, find out how they are getting in, and attempt to remove them and seal up their entry. Do not try to exclude the bats if there are baby bats in the colony. Abandoned baby bats crawl into walls and die, leaving an odor and messy cleanup. If there are no baby bats in the colony, set up a one-way exclusion that will enable bats to escape but not reenter. This can be done with nettings or funnels (bat-cones). Mothballs, ammonia, and ultrasonic sound emitters are fraudulent and are not effective at removing bats from an attic. A bat infestation can contribute to structural damage, as well as health risks. Accumulated guano in an attic can damage a ceiling and should be dealt with quickly and safely.