There is yet another method of rearing larvae to which we must refer--a method known as 'sleeving'--particularly useful when you happen to have the required food plants in your own garden. The ova or larvae are placed on the plant, the whole or part of which is then covered with a bag or 'sleeve' of gauze. The larvae thus imprisoned have the full benefit of fresh air and light, and are also free from the attacks of ichneumon flies. They have a fair amount of liberty, and yet cannot get beyond your reach; also abundance of fresh food without further trouble on the part of the rearer. But even this arrangement is not perfection. It will not suit the night feeders that like to hide beneath the soil during the day, and it interferes somewhat with the burrowing tendencies of those which pupate underground. These little difficulties, however, can be overcome by placing the food plants in large pots or tubs of soil, and tying the mouth of the 'sleeve' round the outside of this utensil. If this cannot be done, those insects that pupate underground must be removed from the plant when their restless disposition shows that the changing time has arrived, and then be transferred to a box of soil where they can find the seclusion they seek. The larvae that hybernate throughout the winter are rather more troublesome, especially those which are inclined to take a ramble on certain mild days in search of food when none is at hand. Still there is no reason why even a beginner should not attempt the rearing of these. They will require food in the autumn until the cold weather sets in, and again early in spring as soon as the new leaves appear; but this is not of much consequence to those who reside in districts where the required food plants abound. Wood feeders also require some special treatment and precautions, and the successful rearing of some is a matter of no little difficulty. A wooden cage is, of course, quite out of the question with these, unless you wish to test the power of their jaws. They must be kept in large pots or jars, covered over with wire gauze or perforated zinc, and supplied with fresh stems or logs of wood, or with moist sawdust fresh from their favourite tree. A few of them--the 'Goat' (page 224), for example--will eat dead and rotting wood, and may be fed on old palings and other waste providing the right kind is selected. The troubles and disappointments of larva rearers are numerous and varied, and commence with the earliest moments of the young insects. Even the hatching period sometimes proves a trial, for it occasionally happens that the young larva has not sufficient strength to bite its way through the shell that surrounds it, and dies with nothing but the surface of its head exposed to view. This may be the result of keeping the ova in too dry a spot, the shell having become too hard and horny for the little creature's jaws.