After the eggs are laid, the two parent beetles crawl out of the hole and cover it carefully up so as to conceal the hiding-place. So far as they themselves are concerned, their only object in all this is to procure food for themselves and their infant young. But the wider effects of such scavenger insects go very far. For we now know that there is no disinfectant so good as the top layer of the soil, which is not really mere dead earth (as most people imagine), but a mingled mass of ramifying life--a little foundation of clay and sand intermixed with endless minute organisms, both animal and vegetable--fungi, bacteria, mites, weevils, and all sorts of petty creatures, which eat up and destroy harmlessly all dead matter subjected to their influence. The earth is thus a most admirable deodorizer and purifier: and burial in its top layers, the body being freely exposed to the rapid action of the devouring microbes, is a most sanitary mode of disposing of refuse. Thus the part that is played in the East by vultures and jackals, or by the wild dogs of Constantinople, is far more effectually and unobtrusively played in our fields and meadows by the many kinds of burying beetles and other insect scavengers. If we remember how great a nuisance a single dead rat becomes in a house, we can faintly picture to ourselves the debt we owe to these excellent and unnoticed little sanitary commissioners. Without them, our fields would not smell so fresh, nor would our flowers bloom so bright; for we must remember that by burying the dead beasts they are not only preventing disease but also manuring the pastures in the best possible fashion. The bones of small animals decay rapidly and make excellent material for the growth of vegetation. The beetles as a rule hunt by night only, and find their prey, as vultures do, by the sense of smell. When they first find it, the male hovers above it like an eagle, circling round and round, so as to point it out to his mate; the female flies straight to it, and buries herself without delay in the rich banquet. But what becomes at last of the buried bodies? No. 3 will show you. The female beetle lays in each body about as many eggs as she thinks it will support. In a very short time the eggs hatch out, and the grubs begin to devour the abundant feast provided for them. The two grubs to the right in the illustration are the young of our friend the orange-banded burying beetle: the one to the left is a larva of an allied form known by the poetical name of Silpha. They set to work at once on the remains of the mouse, and thoroughly strip the bones of every fibre of flesh. As soon as the skeleton is bare, they consider it time to leave off feeding, and pass on to the second stage of their existence--the pupa, or mummy-case. [Illustration: 3.--THE GRUBS UNDERGROUND; FEEDING UPON THE BODY.]