2. Almost all insects become torpid, except those which dwell in the habitations of men, and those that perish and do not survive for a year. They are torpid in the winter. Some conceal themselves for a good while, others only in the coldest days, as the bees, for these also conceal themselves. This is shown by their not touching the food which is prepared for them; and if any of them creep out, they appear transparent, and plainly have nothing in their stomach. They remain at rest from the setting of the Pleiades until the spring. Animals pass their torpid state in warm places, and in the spots they are accustomed to inhabit. CHAPTER XVII. 1. Many sanguineous animals become torpid, as those which are furnished with scales, the serpent, lizard, gecko, and the river crocodile, during the four winter months in which they eat nothing. Other serpents conceal themselves in the earth, but the viper lies hidden among stones. Many fish also become torpid, especially the hippurus and coracinus during the winter; for these alone are never taken but at certain seasons, which never vary. Almost all the rest are taken at all seasons. The lamprey, orphus, and conger conceal themselves. The rock fish conceal themselves in pairs, as the cichla, cottyphus, and perca, the male with the female, in which way also they prepare for their young. 2. The tunny conceals itself during winter in deep places, and they become fattest at this season. The season of capturing them commences with the rising of Pleiades, and continues to the end of the setting of Arcturus. All the rest of their time they remain quiet in concealment. A few of these are taken during the period of their concealment, and so are some other hybernating creatures, if they are disturbed by the warmth of their abode or the unusual mildness of the season. For they come out a little from their holes to feed, and also when the moon is full. Most fish are better tasted during the period of concealment. The primades bury themselves in the mud. This is shown by their not being taken, or their seeming to have a great deal of mud on their backs and their fins pressed down. 3. In spring, however, they begin to move and come to the shore to copulate and deposit their ova. At this season they are captured full of ova, and then also they appear to be in season, but are not so good in autumn and winter. At the same season also the males appear to be full of melt. When their ova are small they are taken with difficulty; but as they grow larger many are taken when they are infested by the œstrus. Some fish bury themselves in sand, others in mud, with only their mouths above the surface. Fishes usually conceal themselves only in the winter. The malacostraca, the rock fishes, the batus, and selache only in the most severe weather. This is shown by the difficulty of capturing them in cold weather.