Even though they don't have a thick layer of blubber, animals such as beavers and sea otters are still able to stay warm when diving in frigid waters. How do they do it? Well, they trap an insulating layer of air between the hairs of their fur. MIT scientists have taken that concept and run with it (or swum with it), creating a bioinspired material that could be used to make lighter, warmer wetsuits.