The bat: misunderstood and maligned

StoryImage( ‘/Images/Story//img-NzfBssKu8H.jpg’, ‘Photo courtesy of’, ‘The biological benefits of bats vary by species. In northern Nevada, most bat species are insectivorous. Estimates indicate that a single little brown bat can catch 1,200 mosquitoes, moths, and other insects in just one hour. Bat populations are declining worldwide due to various factors including loss of or modification of bat habitat.’);

Bats are the only mammals that can fly in the true sense of the word, although there are a few others that can glide through the air for a limited distance. The so-called flying squirrel is an example of a mammal that can glide, but not fly, and is frequently seen in our area.

The wings of bats are totally different in structure from the wings of birds though they develop in a similar embryonic manner. Bat wings consist of a tough, membranous skin supported by the bones of the front limbs and enormously long bones that correspond to the finger bones of a human. All of the bat finger bones, except those of the thumb, serve as braces for the wings; the thumbs, located near the middle of the leading edges of the wings, are free and are used in clinging to surfaces and in crawling.

The “wings” of flying squirrels are not true wings at all, but simply folds of skin along the sides of the body, attached to the front and rear legs. These aerial acrobats can glide a considerable distance by leaping from a tree and spreading the folds of skin and sailing downward.

Bats are probably more feared and misunderstood than any group of animals, including snakes. A plethora of myths and folklore has associated these animals with all that is evil, blood sucking, and transmitting every disease from AIDS to scrofula. As is the usual case, a bit of truth may be found at the root of most folklore stories, which, after being passed along and embellished for generations, are accepted as factual.

Vampire or blood-sucking bats are found only in parts of Latin America, where they prefer the blood of domestic and wild animals over that of humans. Bats found in America north of Mexico feed only on insects with the exception of a few species in the Southwestern states that prefer fruit and nectar.

Bats are active only at night, and this characteristic is responsible for their supposed association with the devil and other evil spirits. These specialized animals have evolved their own system of “radar” to avoid obstacles and to find food in the dark. This phenomenon is called echolocation. A series of ultrasonic sounds are emitted by a bat that creates echoes, which are detected by their sensitive ears.

I would guess that sometime in the past, a bat got entangled in a person’s hair by accident, and the belief that they have a propensity for human hair was born. Bats have been incriminated in the transmission of the deadly rabies virus to man, but most other warm-blooded animals also fall in that category.

There are about 40 species of bats found in the United States with 12 types spending all or part of their lives in Illinois. The Illinois and Mississippi River basins and the cave region in the southern part of the state have the highest bat population because of the abundance of habitat.

All Illinois bats are insectivorous and should be considered friends of man. Studies involving the stomach contents of these flying exterminators have shown a single bat may devour upwards of 3,000 insects in a single night. They have a special liking for pestiferous and dangerous mosquitoes as well as some bugs of economic importance, including the corn borer and cutworm moths.

Many species congregate in large numbers in their roosting and hibernation areas, and if just one individual becomes infected with the rabies virus, many others in the colony may acquire the deadly microbe. Consequently, bats should never be touched with bare hands and certainly not kept as pets.

Years ago, my colleague, Dr. Hugh Keegan, and I became interested in the ectoparasites (ticks, fleas, mites) infesting a large colony of Mexican free-tail bats inhabiting a cave near San Antonio, Texas. We found a large percentage of these bats were infected with a non-human type of malaria, and we hoped to determine how the malarial organism was transmitted from bat to bat. We were unable to establish definitely the mode of transmission, but we did discover and name a new species of scabies mite infesting the population.

Our interest in the bats in this cave abated, however, when a scientist from the Texas State Department of Health, who was also working in the cave, contracted rabies and died when treatment was instigated after he became symptomatic.

Dr. Robert Hedeen is a former resident of Maryland’s eastern shore and resided in the Chicago area from 1960 to 1971. He is a retired professor emeritus of biological sciences in the University of Maryland system. He has published more than 30 scientific papers, has written numerous magazine articles, and is the author of two books on the natural history of the Chesapeake Bay.

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