Frogs and toads are cold-blooded.

This means that their body temperature changes with their surroundings.

To avoid freezing during cold winters, frogs burrow in the mud under a pond

Toads bury themselves in the soil.

Both then fall into a deep sleeplike state called hibernation , until the winter is over.

During hibernation, they do not eat or move.

Their hearts beat slowly. Instead of breathing, they absorb, or take in, through their skin, the oxygen they need.

In areas where summers are very hot and dry, many frogs keep cool in water. But toads must hide from the heat. They dig into the soil and stay there to keep cool. This period of inactivity is called estivation.