Hibernation is when an animal becomes inactive and ““sleeps”” through the cold winter when there is less food. To prepare, many animals eat to gain weight in the summer and fall. The extra fat keeps them alive throughout hibernation. You may already know that mammals like bears, squirrels, and raccoons hibernate. But did you know that many other kinds of animals hibernate too? Frogs, turtles, lizards, snakes, snails, fish, shrimp, and even some insects hibernate or are dormant during the winter!