1297. _Why do moths fly by night?_ Because they are _organised to enjoy subdued light_ and cool air; and as they take very little food during the short life they have in the winged state, they find sufficient by night. Some of the moths, like that of the silk-worm, take no food from the time they escape from the chrysalis until they die. Because, also, they form the food of bats, owls, and other of the night-flying tribes. 1298. _Why are the bodies of moths generally covered with a very thick down?_ Because, as they fly by night, they are liable to the effects of cold and damp. The moths, therefore, are nearly all of them covered with a very thick down, quite distinguishable from the lighter down of butterflies. 1299. _Why do moths fly against the candle flame?_ Because their eyes are organised _to bear only a small amount of light_. When, therefore, they come within the light of a candle, their sight is overpowered and their vision confused; and as they cannot distinguish objects, they pursue the light itself, and fly against the flame. [Verse: "Let him that glorieth glory in this that he understandeth and knoweth me, that I am the Lord which exercise loving-kindness, judgment, and righteousness in the earth: for in these things I delight, saith the Lord."--JER. IX.] 1300. _Why do insects multiply so numerously?_ Because they form the food of larger animals, and especially of birds. A single pair of sparrows and a nest of young ones have been estimated to consume upwards of _three thousand_ insects in a week. 1301. _Why does the "death-watch" make a ticking noise?_ Because the insect is one of the beetle tribe, having a horny case upon its head, _with which it taps upon any hard substance_, the ticking is the call of the insect to its species, just as the noise made by the cricket is a note of communication with other crickets.