bat bonanza

eastern red bat

turning fear into facts.

As Halloween approaches, we thought it was a good time to highlight the native bats of Pennsylvania. Though sometimes considered spooky or frightening, these remarkable mammals are no threat to people. In fact, they are beneficial to us all.

There are nine common bat species in Pennsylvania: big brown, little brown, tricolored, small-footed, long-eared, silver-haired, hoary, eastern red, and Indiana. They range in size from about 15 inches for the hoary bat down to the tiny Indiana bat, which is only about the size of your thumb.

Big brown bats are the most commonly seen in our region, usually just after sunset or right before sunrise during feeding time. They eat agricultural pests, like June and cucumber beetles, and stinkbugs; they also eat ants, stoneflies, mayflies, lacewings, mosquitos, and, occasionally, moths. A small colony of 25 bats can eat a pound of insects every night.

The Ancient Greek word for bat, chiroptera, means “hand wing.” This apt name comes from the animal’s elongated fingers that make up the main structure of the wings. A delicate skin membrane, called the chiropatagium, spans digits two through five. By moving their fingers, they can control the movement of their wings, offering these animals far more flight agility and efficiency than birds or insects.

Big brown bats typically live between six to 19 years in the wild. But bats as an order have been around for centuries. In fact, the oldest fossilized bat ever discovered (found in Wyoming) is an estimated 52 million years old.

Female bats give birth to pups upside down. Most bats only have one pup at a time, largely because the young are born weighing almost a third of their mother’s weight, which means she needs to use a lot of energy to keep them fed, nursing them until they are weaned and transition to insects. Mother bats often fly with their pups. The young cling to their mother’s underarm nipple with their mouths and hang onto her waist with their toes.

While vampire bats are real, they are not present in our region. They live primarily in Central and South America, with some species found in Mexico and the southern U.S. They generally feed on the blood of livestock like cattle, not humans.

If you want more bats around, skip bat boxes. They generally don’t work to attract bats and can spread disease. Instead, turn off your lights at night and plant lots of native plants, which, in turn, attract native insects (and offer food for bats).