These enemies do not come sailing over into the birds' country in ships, or marching up the coast in troops, carrying guns and beating drams and making a great noise. They are cowardly, sneaking enemies. They jump one at a time over hedges and fences, and they crawl under bushes barefoot, and dart across the street when no one is looking. They are so still, gliding on their soft feet, that no one of the bird family can hear them coming. So whole nestfuls of baby birds are gone before their mothers know it. Cats have learned that they are not welcome in our yard. If one of them slips in before we are up in the morning, the birds tell us by a sort of "shriek," and we hurry to help them. We have seen six or seven different kinds of birds crying at a cat and flying at him at one time. They even nip at his back, and dart up so quickly that the cat has no chance to spring at them. The orioles and mocking-birds are our best watch-dogs, screaming with very angry voices at sight of a cat, and warning all the other birds in the yard to "look out." In the orchard there were some stray cats that nobody owned, and we thought it right to shoot the hungry, thieving things. One mocking-bird, who had been robbed once by these cats, would point out a cat to us, flying on ahead, and would not jump away at the sharp bang of the gun. She seemed to understand perfectly well that we were protecting her and aiming at the enemy she feared so much. We have read how wild beasts from the jungle prowl around the homes of India to snatch the children and carry them off. How careful the mothers must be, always watching for the cruel animals and dreading their quick spring! The mother birds in our yard are like those human mothers in India. You have only to watch them when a cat comes prowling around to see how very much like human mothers they are. They scream and dart about in fright, and if you go near they will fly not from you, but toward the cat. They are asking you for help. Birds near your house soon learn to know the family if every one is kind to them, when they have once learned that you are their friend. They will allow you to call while they are eating their meals, or to watch them while nest-building, although they may be almost within reach of your hand. They will even wait around the door for you to shake the tablecloth after dinner, or to throw out the contents of the crumb-pan, hopping about at your feet without a thought of fear. We never can learn all there is to know about birds. We can know only a little about them if we study them all our lives. There is a great professor in a California university who has been trying all his life to get acquainted with fishes, and yet he says he has much more to learn about them. Very little people, like birds and fishes and insects, can interest very great men, and we often see the greatest men the kindest to small creatures.