Why do zebras have stripes?

   The stripes that seem so conspicuous to us probably help zebras to be overlooked by lions and other animals that like zebra meat. Zebras often stand in very tall grass where it is hard to tell the difference between their stripes and the shadows of the grass blades.
   Other creatures have other remarkable ways of hiding from enemies. One kind of grasshopper looks like a leaf — an unappetizing leaf that has already been chewed on by beetles.
   A common garden insect called a walking stick has a body that is easily mistaken for a brown twig. A relative of this walking stick looks like a brier twig, bristling with red thorns.
   One kind of katydid is dotted with imitation dewdrops that make it hard to see, and there is a certain kind of butterfly you can easily overlook. Its wings look just like dead leaves with patches of mold growing on them.
   There are at least two kinds of furry animal that have partners helping them to hide. These partners are tiny plants called algae. They grow on the fur of the animals, and they are green. The green algae make the animals hard to see among the leaves of the trees in the jungles where they live.