All About Bats

The word bat usually suggests a scary creature and thoughts of vampires. However, bats are very helpful creatures. Bats live all over the world, in mines, caves and under bridges. There are over 1500 species of bats. Fifty of these live in national parks. Bats live in bat houses made by people also. Today, bats have come to live in cities. One and one-half million bats live under the Congress Avenue Bridge in Austin Texas.

Some bats hibernate over the winter. By doing this, they can survive when insects are not around. Others fly to milder climates for the winter. Still, others live all year round in a mild climate. Bats which live in trees usually go south for the winter.

During hibernation, a bat's heart rate and breathing rate slow way down. Its temperature may even drop to below freezing. This state of hibernation is called torpor. Bats can even go into torpor for a brief time on a cold day to save energy or up to a month in the winter. During hibernation, bats can be in a state of torpor and then go through a cycle when their body temperatures return to normal. Hibernacula are places where bats hibernate.

Bats belong to a group of mammals called chiroptera, hand-wing. They are the second largest group of mammals, after rats. They are the only mammals which can really fly. Flying squirrels just really glide through the air from tree to tree. Bats eat insects primarily. At dawn and dusk, they swoop through the sky after their prey. Some species eat fish. Some even eat blood. Vampire bats eat blood from mammals like cows. They might drink an ounce a night.

Catching insects while flying is very difficult. Bats use echolocation to help them find insects. Bats emit sound waves at high frequencies. These waves hit objects in their environment and bounce back to the bat. That way they can locate insects. Bats have several kinds of calls. Some are for searching and feeding and some are even social calls. Some bats send out their calls from their noses instead of their mouths. They have special flaps of skin called nose leaves.

A bat's wings are quite complicated. Two thin layers of skin are stretched over its arm and fingers. They have four fingers and a thumb. The fingers are very long compared to the size of their bodies. When bats fly, their stroke is very similar to a butterfly stroke in swimming. They use their wings to wrap around insects or hold fruit while eating.

Bats come out only at night. They are nocturnal. They sleep upside down. They do not like to be alone and sleep in large groups. The largest group of bats is found in Bracken Cave, Texas. Twenty million bats might be there together in the summer. The bats can eat up to two hundred fifty tons of insects in a night. Bats are very helpful to the environment. Because bats are natural insecticides, farmers must spray crops less.

Flying fox and fruit bats are the largest bats in the world. They help people by carrying seeds wherever they fly, then dropping them to create new plants. These seeds can repopulate forests.

Bat pups are born in the spring, one at a time. A mother can sometimes have twins, however. Within a month they can fly. Pups already have strong claws and legs so that they can hold onto their mother. Although bats seem to look like rodents, they are more closely related to humans and primates.