When the hatching has begun, each day adds some hundreds of young bees to the population of the hive, which is not long in becoming too small for the number of its inhabitants. It is then that those curious emigrations of this winged people take place which are called _swarms_. The queen leaves the hive, with a part of her subjects, and founds a new colony elsewhere. In the climate of France the bees generally swarm in the months of May and June. In the south very thickly populated hives may furnish as many as four swarms in a season, but in the north rarely more than one or two. But in some years swarming does not take place at all, for the want of a sufficient population. In such cases the workers do not construct royal cells at the period when the eggs of the males are laid, and the swarming is put off till the following spring. It occasionally happens that a hive, although full of bees, cannot make up its mind to send out a swarm, and also that the hives thinly populated send out abundant swarms. There are, then, other causes than the excess of population which exercise an influence on this annual crisis in the life of bees. The first swarm is always led by the old queen; if other swarms succeed, it is the young females lately hatched who lead the way. There are many signs which announce that a swarm is going to take place. The appearance of the males, or drones, is one of the first signs. Another sign, but far from being infallible, is the excess of the population in the common home. The bees seem then to find themselves so ill at ease in their over-crowded hive, that part of them go out and keep outside, either on the stand upon which the hive is placed, or upon the hive itself. Crowds of bees may be seen heaped up on each other outside, only waiting for the signal of departure. But the least equivocal of all the signs, that which points out the event for the very day, says Réaumur, is when the bees of a hive do not go into the country in as great a number as usual, although the weather may be favourable and seem to invite them to do so. "There is no sign," says Réaumur, "which points out so surely that a swarm is preparing to take flight, as when, in the morning, at those hours when the sun shines, and when the weather is favourable for work, the bees go out in a small number from a hive from which they went out in great quantities on the preceding days, and bring back only a little rough wax. The fact of their acting in this manner seems to force us to concede to bees more intelligence and foresight than many people are inclined to allow that they possess; at any rate, it is exceedingly puzzling to those who wish to explain all their actions by saying that they are purely mechanical. Does it not seem proved that from the morning all the inhabitants of a hive have been informed of the project which will be executed not before noon, or, perhaps, not for some hours after it?... There is a well-known story of an old