Those from Africa are the ones which chiefly devastate Italy; and more than once the Roman people have been obliged to have recourse to the Sibylline Books, to learn what remedies to employ under their existing apprehensions of impending famine. In the territory of Cyrenaica[197] there is a law, which even compels the people to make war, three times a year, against the locusts, first, by crushing their eggs, next by killing the young, and last of all by killing those of full growth; and he who fails to do so, incurs the penalty of being treated as a deserter. In the island of Lemnos also, there is a certain measure fixed by law, which each individual is bound to fill with locusts which he has killed, and then bring it to the magistrates. They pay great respect to the jack-daw, which flies to meet the locusts, and kills them in great numbers. In Syria, the people are placed under martial law, and compelled to kill them: in so many countries does this dreadful pest prevail. The Parthians look upon them as a choice food, and the grasshopper as well. The voice of the locust appears to proceed from the back part of the head. It is generally believed that in this place, where the shoulders join on to the body, they have, as it were, a kind of teeth, and by grinding these against each other they produce the harsh noise which they make. About the two equinoxes they are to be heard in the same way that we hear the chirrup of the grasshopper about the summer solstice. In all these kinds of insects the male is of smaller size than the female. CHAPTER X. ANTS.