Here, then, we have the very best of miners, who has secured food and safety far from the busy world above, and spends his time hunting for grubs and earth-worms in the dark earth below. He is a most voracious animal, and makes the ground above him heave and swell as he toils through it eager for prey, pushing up every now and then with his nose the loose earth he has excavated, thus marking the line of his route by molehills. But when he builds his home and fortress where he takes his long winter’s sleep, and hides from weasels and pole-cats, he takes care to throw no loose rubbish above; on the contrary, he presses the earth together so as to make the walls of his chamber firm and hard, and carries out from it a number of passages, by any of which he can reach his home in safety when he is pursued too closely. Thus by his cleverness in burrowing, and the useful tools which he carries upon his body, the mole has managed to find safe feeding-ground and shelter, when no doubt many of his relations living above ground have been killed off. Even underground he has his enemies, for the Weasel, the Stoat, and the Badger find him good eating, while if he meets one of his own brothers in a narrow passage they will fight till one is killed and eaten; yet though fierce he is also tender-hearted, for mole-catchers say that when a mother-mole is caught in a trap the father may sometimes be found dead by her side. And now if we turn to the _rodents_ for rivals to the mole, we are almost confounded by the multitude of creatures which have found safety in burrowing. Not only have we the rabbit-warrens, by which the sandy soil of our commons is riddled in every direction with holes, leading to burrows where the mother lies snugly hidden with her five or six naked little ones in a bed of her own fur; but we have the extensive burrows of the little, long-legged, leaping, gnawing Jerboas of Africa, which are so like the Jumping Shrews among insect-eaters. Then again there are the underground cities of the South American Viscachas and Chinchillas, and the extensive subterranean settlements of the Lemmings,--those curious rodents, which from time to time start off in vast swarms across Norway, over mountain and valley, through flood and fen, over rivers and plains, preyed upon by eagles and hawks, foxes and weasels, on their way, but never stopping or swerving in their course till they reach the sea, into which they plunge and drown themselves. Again, every inhabitant of Switzerland knows the Marmot and the burrows he forms, scratching up the earth with his hind feet and patting it together with his front paws and his broad nose; while every American child has heard of the hillocks thrown up by the “Prairie Dogs,”[138] which undermine whole plains in the far west with their underground cities, where the burrowing owl shares their home with them, and the rattlesnake steals their young. [Illustration: Fig. 58.