"Bats in the Attic. This is the term used most often by our customers calling to seek help with a bat issue. In most cases, however, the bats are not actually populating the attic proper. Bats only need a small opening, roughly a quarter inch, to gain entry to the gaps between the inside wall of a structure and the exterior fascia. In almost every instance, the bats will take up residence in a gap that is located outside of the attic space. Having said that, it does not rule out the possibility that a confused (usually young) bat has crawled through a twenty foot maze of gaps and now finds itself hanging from the wall of your livingroom.
The Bats of Florida. Brazilian Freetail Bats (Tadarida brasiliensis) and Evening Bats (Nycticeius humeralis) are the two most common colonizing bats we deal with in Central Florida. In total, there are 13 species of bats found in Florida. Some bats are year round residents while others simply visit seasonally.

Free-tail and Evening Bats will typically choose a manmade structure in which to colonize. Their colonies can quickly populate to numbers from the hundreds all the way up to thousands of members. Along with the noise of the bats crawling across wooden surfaces comes some very serious health risks associated with the accumulations of urine and droppings.
• Bats are insectivores dining mainly on moths and flies. Some larger colonies have been estimated to consume thousands of pounds of insects per night. That's amazing!

• Life span in most cases is 12 to 25 years, but some species of bats can exceed 40 years.

• Home range is typically within several hundred yards of the home colony.

• Florida adult bats normally measure less than 3 inches in body length with a wingspan of 13 inches.

• Baby bats are born in the summer months, usually in early June. Most species of bats produce one live offspring per year. This slow reproductive rate is the cause for much legislation to protect the species.
More on The Bats of Florida: Brazilian Freetail Bats (Tadarida brasiliensis) and Evening Bats (Nycticeius humeralis).

Bats are a vital part of our lives in Florida and should be appreciated. They are intelligent, shy creatures that quietly work at making our lives less troubled by consuming literally tons of flying insects each night. Each bat will consume its own bodyweight in insects per outing.

Bats do not dive-bomb humans and get stuck in your hair. On a warm summer evening, have you ever noticed a small squadron of gnats or mosquitos circling above your head or that of a companion? That is exactly what the bat is after...not you, your hair, or your jugular.

Bats are not blind. Their eyesight is comparable to that of our own. They supliment their vision by using a form of echolocation that enables them to hunt and maneuver at incredible speeds.
Noise: A very high pitched squeaking or chirping sound is often the first tip to the home owner that something has moved into the roof area. Sometimes the movement of the bats can be detected as a scratching or scurrying sound.
Structural Damage: In order to enter the void in which the colony lives, bats will exploit any openings 1/4" or bigger that leads to that space. Over time one or two openings in particular will become the main points of entry and exit. As the bats travel over that spot time and time again, they will leave a grease trail that can easily be viewed from the ground. These stains are often the first sign that a significant colony exists within your structure.

The damage caused by having dozens, hundreds, or thousands of bats existing in a confined space within a structure can be easily imagined. Although they tend to evacuate on the way out of the roost site and again on the way in, they still spend a large portion of the day pooping and urinating within your wall space. They also possess a scent gland that produces a very musky, almost chemical, odor that can help identify the roost site.
Droppings: The droppings left by the colony can be extremely dangerous to humans. Bat guano is known to carry a fungus that can have serious respiratory effects on humans. A decontamination of the effected area is recommended whenever possible.
Recurrence: A structure that is not treated properly can expect to have a reinfestation in very short order.
Exlusion: The best and only legal means of dealing with a bat infestation. All secondary entry points are sealed prior to removing the colony. These points, if untreated, would allow the bats to re-enter after they are evicted. Once the secondary gaps are sealed, the colony can be removed through the installation of a one-way exclusion device that will allow the colony to exit for a food and water source but prevents re-entry. All bats will leave exit the site within four days, the device can be removed, the final hole sealed and the clean-up can begin.
Copyright Wildlife Ranger 2014