Hibernation is when some animals go into a deep sleep to survive winter without food. Any mammal that remains inactive for many weeks with a body temperature lower than normal may be in hibernation.
Aestivation occurs when animals, such as snails, face hot, dry seasons when food and moisture are scarce. These animals will find themselves a safe place to sleep in order to survive high heat and lack of water in their environment.
Migration occurs among animals, such as birds, when they need to travel to a warmer place to find food. An example is the Canada goose.