I've gotten several notes from readers who say they have "bat problems." I'm not sure whether it's been a good year for bats or whether we're just noticing them more, but I do my best to convince people that having bats around is a "bonus" rather than a difficulty.

Americans have a peculiar attitude toward these little flying mammals, much of it probably biased by accounts from Dracula, Indiana Jones, and midnight horror movies. Many people view bats as threats to life, limb, and mental health, which is not the outlook held by Europeans.

In Europe, bats are welcomed as major controllers of insect pests, and most countries there have strict laws to protect bats and roosting areas. By comparison, Americans despise bats even as they cruise night skies in pursuit of pestiferous insects we despise even more. Nearly all of us get irritating bites from mosquitos, but I'll wager than less than one in 10,000 people has ever been molested by a bat, and then it was probably the person's own fault.

Our solution to mosquito problems has been to drain valuable wetlands where they happen to breed, to spray ecologically hazardous pesticides, and to erect those unearthly blue bug-whacker lights that sizzle on contact with every flying insect--except mosquitoes, which are NOT attracted to light. It seems to me we could do better by encouraging bats to roost near our homes so they could silently spend the night zapping bugs at no cost to anyone.

Several York Countians have noticed bats in the eaves of their houses this summer, particularly in louvered slats that cover ventilation screens. Bats seem to seek out these areas, perhaps because the flow of air is cool and similar to that in caves. Last week near Epinport School in Rock Hill SC, I found nearly 50 bats roosting in attic louvers at a private residence. Neville Yoon, a student of mine who lives in the house, helped capture a few of the bats for identification purposes. All appeared to be Big Brown Bats, Eptesicus fuscus, a species that is widespread but not necessarily common over a range including most of North America.

Some of the female bats were nursing young that were less furry but almost as big as they were. Most Piedmont bats mate in the fall, and females store sperm while they hibernate through the winter. Actual fertilization probably occurs during the last stages of hibernation, and offspring are nourished by milk enriched by the first succulent bugs of spring. In migratory bat species, of which we have some, mating usually occurs in spring, and young are born later in summer.

Disturbing hibernating bats in caves and attics is one way to wipe them out, and it must be avoided. When hibernators are awakened, they burn off huge amounts of precious energy needed for the rest of the winter, so they often simply die before spring arrives. I heard of one northern roost in which 250,000 hibernating bats were destroyed accidentally by recreational cavers who shined their lights on cave ceilings. It's not just coincidental that people who lived near the cavern noticed a tremendous increase in mosquitos the following summer.

A common misunderstanding about bats is that they are flying rodents; not so. Rodents have large buck teeth with two incisors on top and two on bottom; mice, gerbils, and beavers are examples. Bats often have no incisors at all, but their other teeth (including molars) are sharply pointed and adapted for crunching up insects. In this way, they are more closely related to Insectivores (shrews and moles), with which they were once classified.

All bats now are placed in the taxonomic order Chiroptera, from the Latin for "hand" (as in "chiropractor," or one who heals with his hands) and "wing." Indeed, the wing of a bat is made mostly of a living membrane of skin stretched over incredibly elongated fingers; the thin membrane also covers bones of the relatively short forearm and upper arm, providing a large surface area for flying.

Of all the animals in the world, only bats, birds, and insects have successfully conquered the air. (So have humans, of course, but we needed machinery to do it.) Other fauna that may zoom overhead are merely gliding and are unable to gain altitude, as in "flying" squirrels and "flying" fish. Bats are rather slow flyers with amazing aerobatic skills enabling them to do barrel rolls or nearly stop dead in the air. They chase insects with pinpoint accuracy, catching small prey in their mouths and large insects in a tail membrane with which they cup captured bugs that are eaten in flight.

Prey items are found by echolocation in which the bat sends out a high-pitched tone and listens for its return; a quick echo indicates an stationary object nearby, small echoes bounce from insects. The typical pug nose and large ears of the bat help produce or receive the signal.

Because bats are nocturnal and relatively difficult to capture alive, not much is known about their distribution and abundance. Only 13 species have been reported from South Carolina, and just eight of these are known from the Piedmont. These include the Southeastern Myotis (known only from one specimen in a Camden mill), Silver-haired Bat, Eastern Pipistrelle, Red Bat, Seminole Bat, Hoary Bat, Evening Bat, and the Big Brown Bat.

On summer evenings I can see Red Bats leave my attic to fly over Hilton Pond in search of supper, and Northwestern students have brought me this species, Hoary Bats, and Big Brown Bats. Generally, I maintain the bats for several days, feeding them to be sure they are well. It's always exciting when I close the classroom shades and dim the lights, allowing the bat to fly around and demonstrate its aerial prowess. This poses no real danger to the students or the bat; the bat avoids flying into students, and I doubt any student will ever run into a bat.

(At this point I am bound to mention that we once had a classroom bat named "Lou," which is short for "Louisville Slugger." This is a terrible pun that I'd rather not dwell on further!)

Two main problems attributed to bats--rabies and histoplasmosis--have been distorted and magnified by folk tales and misinformation. I don't wish to imply that bats never cause health problems, but they are not nearly as dangerous as many other wild mammals, or even some domestic ones.

Bats do carry rabies, but they are almost never responsible for cases of the disease in humans. I don't recommend that people run around picking up every bat they can find, but unless the bat is acting strangely or is noticeably sick, it probably will not transmit the disease. Bats, however, are unlike most mammals in that they often carry rabies without succumbing to it. Typically, I exercise caution and wear a leather work glove while handling bats, but some of my long-term captives become so calm I can hand-feed them crickets and mealworms.

If large quantities of bat droppings (guano) get into the soil, the fungus Histoplasma may flourish. This fungus also grows rarely on moist lung linings of persons with lowered resistance to infection, but you are much more likely to pick it up from pigeon roosts or floors of chicken houses. Some readers have mentioned there are a few bat droppings on or under the eaves of their houses, but these small deposits can be swept or rinsed away and are unlikely to harbor disease.

Obviously, the benefits of bats far outweigh any detriments. All our Piedmont bats are insect eaters; they don't suck blood, and it's doubtful they'll fly into your hair unless you stick your head right under a streetlight where bats are chasing bugs.

Next time someone claims you have bats in YOUR belfry, consider it a blessing.

Back to Piedmont Naturalist Volume 1 (1986)