Kevin Brewer, age 11, of New Bedford, Mass., for his question:

CAN TURTLES HIBERNATE UNDERWATER?

Turtles, like other cold blooded reptiles, cannot stay active in cold weather. Species that live in areas that have harsh winters must hibernate.

Most fresh water turtles hibernate by burrowing into the warm muddy bottom of a pond, stream or other body of water. Land turtles bury themselves in soil or under rotting vegetation. Breathing during this period of hibernation isn't necessary for the animals.

Some species of turtles survive hot, dry periods by going into a state of limited activity called estivation. Estivation somewhat resembles hibernation.

There are about 240 different kinds of turtles, with about 50 living in North America.