Picture a polar bear. White, right? Surprise! If you could peek under all that fluffy fur, you'd find skin that is black. You can even see a clue on the outside. Just look at a polar bear's nose!
Here's the next twist. The fur isn't truly white either. A polar bear's coat has two layers. Close to the skin is a soft, thick undercoat. On top are longer hairs called guard hairs, and they're hollow. Both kinds of hair are see-through, kind of like clear plastic straws.
So why does the bear look white? Each hair has tiny air spaces inside. When sunlight hits them, the light bounces around and scatters in every direction. All that scattered light reaches our eyes looking white. It's the same reason snow looks white even though a single bit of ice is clear. Sneaky, right?
That white look is super handy. It helps the bear blend in with the snow and ice. And the black skin helps too, because dark colors are great at soaking up the sun's warmth. That's a big deal when you live in the freezing Arctic.
Polar bears even have fur on the bottoms of their paws! It keeps their feet warm on cold ice and helps them grip so they don't slip like a dad on a skating rink.
Ask your kid: If you wore a black shirt and a white shirt on a sunny day, which one would make you feel warmer?
