Scientists at MIT studied beavers to create a new rubbery material that could be used to make lighter and warmer wetsuits.

Beavers stay warm and dry underwater because their dense layers of fur trap pockets of warm air. Inspired by these creatures, the scientists experimented with different hair densities until they figured out the optimal space between hairs to create fur-like pelts.

Source (Siyi Chen, “MIT scientists are creating a lighter, warmer wetsuit inspired by beavers”, Quartz, 10.10.2016)