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B Y this time I am sure you think that all the small bugs, flies, spiders, and crabs will soon be dead. You have found how cold kills them. You have heard how they kill each other. You know that men and birds and beasts kill them.
How can any live? What is there to save the poor things? The two chief things that save them are their shape and their color. Why, how is that? Let us see how shape and color protect these living things.
On the sand by the sea the crab that lives mostly out in the air is of a gray color. It has fine red spots like sand. The shell of this crab looks so much like sand that, if he lies flat and still, you can scarcely see him.
The crab that lives on the sea-side mud is black-green like the mud. Birds cannot see him very well, he is so like the mud that he lies upon.
The spiders that live in the woods have the color of a dead leaf.
Some of them, as they lie in their webs, fold up their legs and look like a dead leaf. One spider puts a row of dead leaves and moss all along her web. She lies on this row, and looks like part of it. Birds cannot see her, as she lies in this way.
One small bee that lives in trees is green, like a new leaf. The bees, in brown, black, and gold, look like parts of the flowers on which they alight.
Birds and beasts that live in snow lands are often white, as the polar bear and the eider duck.
Snakes that live on trees, or on the ground, are often brown or green. They look like the limbs of trees.
Little lizards in walls are gray like stone. In woods, they often are the color of a dead twig. They can fold up, or stretch out, and look like twigs, or leaves, or balls of grass or hay.
All this will keep them from being seen by animals that would kill them.
Some of them, you know, have hard shells to shield them. Did I not once tell you how fast they move? They dart, and run, and jump, quick as a flash of light. That helps them to get out of the way.
Did I not tell you, also, that the crab has his eyes set on pegs? He can turn them every way to see what is near him.
The insect and the spider do not have their eyes on long pegs. Some kinds have six or eight eyes. These eyes are set in a bunch, and some face one way, some another. They can see all ways at once.
Then, too, so many small live things grow each year, that they cannot all be put out of the way.
Each crab will lay more eggs than fifty hens. One spider has more baby spiders than you can count. One bee has more new bees in the hive each year than there are people in a large city. In a wasp's big nest there are, no doubt, as many wasps as there are leaves on a great tree.
Of the creatures which it is most easy to kill, very many are born. And so, while many of them perish each day, many are left to live.