They have a great aversion to bad smells, and fly away from them; a dislike which extends to artificial perfumes even. Hence it is that they will attack persons who smell of unguents. They themselves, also, are exposed to the attacks of wasps and hornets, which belong to the same class, but are of a degenerate[68] nature; these wage continual warfare against them, as also does a species of gnat, which is known by the name of “mulio;”[69] swallows, too, and various other birds prey upon them. Frogs lie in wait for them when in quest of water, which, in fact, is their principal occupation at the time they are rearing their young. And it is not only the frog that frequents ponds and streams that is thus injurious to them, but the bramble-frog as well, which will come to the hives even in search of them, and, crawling up to the entrance, breathe through the apertures; upon hearing which, a bee flies to the spot, and is snapped up in an instant. It is generally stated that frogs are proof against the sting of the bee. Sheep, too, are peculiarly dangerous to them, as they have the greatest difficulty in extricating themselves from the fleece. The smell of crabs,[70] if they happen to be cooked in their vicinity, is fatal to them. CHAP. 20.—THE DISEASES OF BEES. Bees are also by nature liable to certain diseases of their own. The sign that they are diseased, is a kind of torpid, moping sadness: on such occasions, they are to be seen bringing out those that are sick before the hives, and placing them in the warm sun, while others, again, are providing them with food. Those that are dead they carry away from the hive, and attend the bodies, paying their last duties, as it were, in funeral procession. If the king should happen to be carried off by the pestilence, the swarm remains plunged in grief and listless inactivity; it collects no more food, and ceases to issue forth from its abode; the only thing that it does is to gather around the body, and to emit a melancholy humming noise. Upon such occasions, the usual plan is to disperse the swarm and take away the body; for otherwise they would continue listlessly gazing upon it, and so prolong their grief. Indeed, if due care is not taken to come to their aid, they will die of hunger. It is from their cheerfulness, in fact, and their bright and sleek appearance that we usually form an estimate as to their health. (19) There are certain maladies, also, which affect their productions; when they do not fill their combs, the disease under which they are labouring is known by the name of _claros_,[71] and if they fail to rear their young, they are suffering from the effects of that known as _blapsigonia_.[72] CHAP. 21.—THINGS THAT ARE NOXIOUS TO BEES.