Think how many insects and worms a toad could destroy in a single summer. Practically every insect and worm destroyed adds to the produce of the garden and the farm, or takes away one cause of discomfort to men and animals. One observer reports that a single toad disposed of twenty-four caterpillars in ten minutes, and another ate thirty-five celery worms within three hours. He estimates that a good-sized toad will destroy nearly 10,000 insects and worms in a single summer. [Illustration: _Fig. 118. Two newts feasting on tadpoles._] ENEMIES--THE SHADOW SIDE OF LIFE. [Illustration: _Fig. 119. In danger from a crow._] So far nothing has been said about the troubles and dangers of the toad's life. Fig. 111 is meant to show the main phases in the life-history. If one looks at it perhaps he may wonder what becomes of all the tadpoles that first hatch, as only two toads are shown at the top. Is not this something like the other life-histories? How many little robins or chickens die and never become full-grown birds! Well, the dangers to the toad begin at once. Suppose the eggs are laid in a pond that dries up before the little toads can get ready to live on the land; in that case they all die. The mother toads sometimes do make the mistake of laying the eggs in ponds that dry up in a little while. You will not let the artificial pond at the school-house dry up, will you? Then sometimes there is an especially dry summer, and only those that transform very early from tadpoles to toads are saved. In the little picture (Fig. 118) is shown another source of danger and cause for the diminution in numbers. The newts and salamanders find young tadpoles very good eating and they make way with hundreds of them. Some die from what are called natural causes, that is, diseases, or possibly they eat something that does not agree with them. So that while there were multitudes of eggs (1,000 or more from each toad), and of just hatched tadpoles, the number has become sadly lessened by the time the brood is ready to leave the water. Then when they set foot on land, their dangers are not passed. They may be parched by summer's heat or crushed under the feet of men or cattle. Birds and snakes like them for food. Figs. 119 and 120 show some of these dangers. Is it a wonder, then, that of all the multitudes of tadpoles so few grow up to be large toads? We have so few helpers to keep the noxious insects in check, it is not believed that any boy or girl who knows this wonderful story of a toad's life will join the crows, the snakes and the salamanders in worrying or destroying their good friends. MOULTING AND HIBERNATION. There are two very interesting things that happen in the life of many of the lower animals; they happen to the toad also. These are moulting, or change of skin, and hibernation, or winter sleep. Every boy and girl ought to know about these, and then, if on the lookout, some or all of the things will be seen.