Mark and his dad live in New York. When the weather is warm, they like to go outside. Lots of people like to do that. They also like to do something that many people never do. They like to explore caves.
This year, however, Mark and his dad can't explore the caves near them. Scientists in the state have asked people to stay out of caves and mines where bats are living or might have been hibernating. Many bats have disappeared or died as a result of a disease, and no one knows why for sure. Scientists want everyone to be careful. Even scientists go into caves with respirators and clean clothing in case people can spread the disease to bats.
Mark was surprised that scientists knew bats were disappearing. Most people Mark knows don't like to even think about bats. They think that bats are ugly and scary. Mark, though, knows bats are important. Mark knows that one bat can eat 3,000 flying insects on a summer night. Some of these bugs are ones that eat crops on farmland.