An Arlington Heights resident called for help from the police animal
warden for a bat in the basement in the 1100 block of West Miner
Most microbats are active at night or at twilight.
Many bats migrate, while others pass into torpor in cold weather but rouse themselves and feed when warm spells permit insect activity. Others retreat to caves for winter and hibernate for six months.
The social structure of bats varies, with some bats leading a solitary life and others living in caves colonized by more than a million bats. The fission-fusion social structure is seen among several species of bats. “Fusion” refers to the grouping of large numbers of bats in one roosting area and “fission” is the breaking apart and mixing of subgroups, with individual bats switching roosts with others and often ending up in different trees and with different roostmates.
Studies also show that bats make all kinds of sounds to communicate with others.
Bats and Disease
Bats are natural reservoirs or vectors for a large number of zoonotic pathogens including rabies, severe acute respiratory syndrome (SARS), Henipavirus (ie. Nipah virus and Hendra virus) and possibly ebola virus. Their high mobility, broad distribution, social behavior (communal roosting, fission-fusion social structure) and close evolutionary relationship to humans make bats favorable hosts and disseminators of disease. Many species also appear to have a high tolerance for harboring pathogens and often do not develop disease while infected.
Only 0.5% of bats carry rabies. However, of the very few cases of rabies reported in the United States every year, most are caused by bat bites. Although most bats do not have rabies, those that do may be clumsy, disoriented, and unable to fly, which makes it more likely that they will come into contact with humans. Although one should not have an unreasonable fear of bats, one should avoid handling them or having them in one’s living space, as with any wild animal. If a bat is found in living quarters near a child, mentally handicapped person, intoxicated person, sleeping person, or pet, the person or pet should receive immediate medical attention for rabies. Bats have very small teeth and can bite a sleeping person without detection.
If a bat is found in a house and the possibility of exposure cannot be ruled out, the bat should be sequestered and an animal control officer called immediately, so that the bat can be analyzed. This also applies if the bat is found dead. If it is certain that nobody has been exposed to the bat, it should be removed from the house. The best way to do this is to close all the doors and windows to the room except one to the outside. The bat should soon leave.
Due to the risk of rabies and also due to health problems related to their guano, bats should be excluded from inhabited parts of houses. For full detailed information on all aspects of bat management, including how to capture a bat, what to do in case of exposure, and how to bat-proof a house humanely, see the Centers for Disease Control’s website on bats and rabies. In certain countries, such as the United Kingdom, it is illegal to handle bats without a license.
Where rabies is not endemic, as throughout most of Western Europe, small bats can be considered harmless. Larger bats can give a nasty bite. They should be treated with the respect due to any wild animal.
By emitting high-pitched sounds and listening to the echoes, also known as sonar, microbats locate prey and other nearby objects. This is the process of echolocation, an ability they share with dolphins and whales. Two groups of moths exploit the bats’ senses: tiger moths produce ultrasonic signals to warn the bats that the moths are chemically-protected (aposematism) (this was once thought to be a form of “radar jamming”, but this theory has been disproved); the moths Noctuidae have a hearing organ called a tympanum which responds to an incoming bat signal by causing the moth’s flight muscles to twitch erratically, sending the moth into random evasive maneuvers.
Although the eyes of most microbat species are small and poorly developed, their sense of vision is typically very good, especially at long distances, beyond the range of echolocation. It has even been discovered that some species are able to detect ultraviolet light. Their senses of smell and hearing are excellent.
The teeth of microbats resemble those of the insect eaters. They are very sharp in order to bite through the hardened shell of insects or the skin of fruits.
While other mammals have one-way valves only in their veins to prevent the blood from flowing backwards, bats also have the same mechanism in their arteries.
The finger bones of bats are much more flexible than those of other mammals. One reason is that the cartilage in their fingers lacks calcium and other minerals nearer the tips, increasing their ability to bend without splintering. The cross-section of the finger bone is also flattened instead of circular as is the bone in a human finger, making it even more flexible. The skin on their wing membranes is a lot more elastic and can stretch much more than is usually seen among mammals.
Because their wings are much thinner than those of birds, bats can maneuver more quickly and more precisely than birds. The surface of their wings is also equipped with touch-sensitive receptors on small bumps called Merkel cells, found in most mammals, including humans. But these sensitive areas are different in bats as each bump has a tiny hair in the center, making it even more sensitive, and allowing the bat to detect and collect information about the air flowing over its wings. An additional kind of receptor cell is found in the wing membrane of species that use their wings to catch prey. This receptor cell is sensitive to the stretching of the membrane. The cells are concentrated in areas of the membrane where insects hit the wings when the bats capture them.
One species of bat (A. fistulata) has the longest tongue of any mammal relative to its body size. This is extremely beneficial to them in terms of pollination and feeding – their long narrow tongues can reach deep down into the long cup shape of some flowers. When their tongue retracts, it coils up inside their rib cage.
More info …
Bats and Rabies | CDC Rabies