The water carriers are the bees who fly backwards and forwards between some neighbouring stream and the hive, supplying it with the water necessary to the workers. A hive should be placed near a stream or river, so that the bees may have as much water as they want, and they are helped in this if the stream be a shallow one in which there are little pebbles and rocks so that they can easily sip up the water. Another class of workers are the chemists, whose duty it is to place a tiny drop of acid, from their poison-bag, into each cell of honey, before it is finally sealed over. The acid supplied is chiefly what is called formic acid, and this is a very good preservative; it serves to keep the honey fresh and sweet until it is wanted. You will remember that we said that it was actually good for us to be stung. This is because the formic acid which is pumped into the wound by the bee mixes with our blood, and prevents rheumatism. You will hardly ever find that a bee-keeper is troubled with this complaint. CHAPTER XXV THE COMB BUILDERS In order to trace the history of a hive, and to learn about the round of work which goes on day by day, we will suppose that a swarm of bees has been placed in an empty hive. We shall then be able to follow them as they commence with the first necessary work of building the combs. Our later chapters will lead us through the whole cycle of hive life. We have already seen how the frames are placed within the hive, but we have yet to learn how the combs are built in them. Before the builders can set to work, however, it is necessary that the wax, of which the combs are constructed, should be made. When a swarm of bees first enters the empty hive, numbers of them climb to the roof, and fasten themselves, by means of their tiny claws, to points of vantage. Other bees then join them, each hooking its claws in the claws of another, and in this manner chains of living bees hang from the roof in festoons. As time goes on these chains become more numerous, until the hanging bees look like a large cluster, for the chains cross and intertwine. All the bees do not form themselves into chains, for guards are posted at the hive door, while others examine every corner of their new home. The scavengers have to clean the floor and carry away twigs or gravel, so that everything shall be perfectly tidy for the builders to start work.