During the winter, at least for three months, the polar bear takes no food, but lives entirely upon the store of fat which her body had accumulated before she went into retirement. The same is true of many hibernating animals, but in case of the bears it is more remarkable because the mother bear must not only support herself but nourish her young for a long period without taking any food for herself.
Another good example of a ground-dweller is the aard vark of Southern Africa. He is as curious as his name, and scoops out immense quantities of earth to form his home. This dwelling might be termed a cave, as he heaps up the earth in the shape of a mammoth artificial ant-hill; on one side is the entrance, which is so skilfully formed that it looks far more like the work of man than of an animal.
His name is Dutch and means earth-hog. It is applied to him because his head looks somewhat like that of a pig. His claws are powerful and enormous, and with them he is able to dig into the hardest soil, and to destroy the giant ant-hills which are dotted over the plains of South Africa, and which can withstand the weight of a dozen men.
This strange creature sleeps during the day, and comes forth at evening to seek his food. The first thing he does is to burst a hole in the stony side of an ant-hill, to the utter dismay of its tiny inhabitants. As they run among the ruins of their fallen city, he throws out his slimy tongue and catches them by the hundreds. In a short time only the shell of a half-destroyed wall remains.
These once stately ant-homes metamorphosed into caves, form homes for the jackals and large serpents of the plains. The Kaffirs of Africa use them as vaults into which are thrown their dead. The aard vark outrivals, with his great claws, the most skilled burrowing tools of man. These animals are therefore rarely captured. It is not uncommon for a horse to fall into their excavations and be killed.
Miners, excavators, and underground dwellers teach us the great lesson that, while many of them sought the ground as a protection, and found there many difficulties to overcome, they not only have won in the great struggle of life but have so skilfully adapted themselves to their environment and surroundings as to become entire masters, even artists, in their methods of living.
VI
ANIMAL MATHEMATICIANS
"But what a thoughtless animal is man,—
How very active in his own trepan!"
—Prior.