In spraying fruit trees to prevent disease you should always avoid spraying when the trees are in bloom, since the poison of the spray seriously endangers the lives of bees. The eggs laid by the queen, if they are to produce workers, require about twenty-one days to bring forth the perfect bee. The newly hatched bee commences life as a nurse. When about ten days old it begins to try its wings in short flights, and a few days later it begins active work. The life of a worker bee in the busy season is only about six weeks. You may distinguish young exercising bees from real workers by the fact that they do not fly directly away on emerging from the hive, but circle around a bit in order to make sure that they can recognize home again, since they would receive no cordial welcome if they should attempt to enter another hive. They hesitate upon returning from even these short flights, to make sure that they are in front of their own door. [Illustration: FIG. 266. GOOD FORM OF HIVE] There are several kinds of enemies of the bee which all beekeepers should know. One of these is the robber bee, that is, a bee from another colony attempting to steal honey from the rightful owners, an attempt often resulting in frightful slaughter. Much robbery can be avoided by clean handling; that is, by leaving no honey about to cultivate a taste for stolen sweets. The bee moth is another serious enemy. The larva of the moth feeds on the wax. Keep the colonies of bees strong so that they may be able to overcome this moth. [Illustration: FIG. 267. ANTI-ROBBING ENTRANCE _st_, stationary piece; _s_, slide; _p_, pin, or stop] Queenless or otherwise weak colonies should be protected by a narrow entrance that admits only one bee at a time, for such a pass may be easily guarded. Fig. 267 shows a good anti-robbery entrance which may be readily provided for every weak colony. Mice may be kept out by tin-lined entrances. The widespread fear of the kingbird seems unfounded. He rarely eats anything but drones, and few of them. This is also true of the swallow. Toads, lizards, and spiders are, however, true enemies of the honeybee. EXERCISE Can you recognize drones, workers, and queens? Do bees usually limit their visits to one kind of blossom on any one trip? What effect has the kind of flower on the flavor of the honey produced? What kinds of flowers should the beekeeper provide for his bees? Is the kingbird really an enemy to the bee? SECTION LIX. WHY WE FEED ANIMALS In the first place, we give various kinds of feed stuffs to our animals that they may live. The heart beats all the time, the lungs contract and expand, digestion is taking place, the blood circulates through the body--something must supply force for these acts or the animal dies. This force is derived from food.