In both ants and bees we find solitary and social species, so as in ants we have been considering the latter only, we will now reverse the process with bees. There are many interesting species of solitary bees, but it must be premised that the word “solitary” is to be understood here in a special rather than in a general sense. As far as mere numbers are concerned, there is often a large community of bees building their cells in close proximity all at the same time, but each builds its cell for itself alone, or rather for its family—no one thinks of helping its neighbour. There is no co-operation, in fact, and that makes all the difference. It would be all the same to every one of the bees that are building so close together if all the rest went away and left it to work alone. And yet we cannot even quite say this, because, in one case, at any rate, though every individual bee makes its own cell and thinks only of that and of its own family, yet, when all the cells are finished, the whole community join in making one mud roof over the whole of them. By this we see how difficult it is to find quite separate places for allied animals, and how the habits of one are apt to slide gradually into those of another. Still, we must do the best we can, and take words as we find them, remembering that the locusts, as already explained, do _not_ belong to the _locustidæ_. ------------------------------------------------------------------------ [Illustration: DRIVEN OUT BY HORNETS.] [Illustration] Aelian, in his “Natural History,” says that a city in Crete was attacked by such a plague of hornets that the inhabitants were driven to abandon it, and build a new city on another site. A hornet is shown to the right of this inscription.