Origins & Diversity

Bats have been around for quite a long time. Bat fossils date back to the Eocene Epoch about 50 million years ago, which means that bats probably originated about the time dinosaurs were disappearing. There are around one thousand species of bats, so they make up nearly one-quarter of all mammal species! Bats are found on every continent, except Antarctica. Most bats live in the tropics, where food is available year round. There are over 40 species of bats in America, and nine that regularly live in Pennsylvania.

Bats are divided into two main groups: megabats and microbats.

Megabats

• Are usually larger
• Many are active during the day
• Very few "echolocate," instead they use vision and their sense of smell to find food
• Most are fruit, pollen, or nectar eaters
• They usually don't hibernate
• Megabats are usually found in tropical areas of Asia, Africa, and Australia
• Flying foxes belong to this group.

• Are smaller
• Mainly active at night
• Use echolocation
• Primarily eat insects
• Many hibernate in winter
• Microbats are a diverse group that is found worldwide
• All U.S. bats are microbats.

Bats are valuable economically and ecologically, as insect controllers, pollinators, and seed dispersers. Bats reduce the populations of many agricultural pests, including corn borers, grasshoppers, and cutworm moths. A colony of 1000 bats could consume over 4 million insects a season! They are responsible for pollinating the wild stock of many economically valuable crops such as cashews, bananas, and mangoes. Bat seed dispersal plays an important role in tropical reforestation, and it is well known that bat guano (manure) makes a great fertilizer. Bat studies have also contributed to the development of navigational aids, vaccines, and surgical procedures.