Book 11, Question 134
Why Do Wood Frogs Freeze in Winter and Thaw?
Wood frogs freeze in winter and thaw in spring because sugars in their bodies work like antifreeze! Their hearts stop beating and ice forms around their cells, but they wake up again when it warms up. They live in forests across Canada and the northern United States.
More fun facts
- Wood frogs freeze solid in winter and come back to life in spring.
- They hibernate under leaves near the surface and freeze and thaw with their surroundings.
- When ice reaches a wood frog, its skin freezes and ice pulls water out of its cells.
- The frog's liver makes lots of glucose, a sugar that props up the cells.
- There is no ice inside the cells.
- While frozen, the frog has no heartbeat or brain activity until it thaws.
Sources: National Geographic, Smithsonian
Questions kids ask
Why do wood frogs wake up early in spring?
The forest ground where they hibernate thaws earlier than ponds and mud.