E SHARP CLAWS OF THE GROUND SQUIRREL ARE EFFICACIOUS
TOOLS IN DIGGING HIS COSY UNDERGROUND BURROW.]

There is no danger that the bears will stifle for air under the snow,
because the warmth of their breath always keeps a small hole open at
the top of the snow-cell. This snow-house increases as time goes on, the
heat exhaled from their bodies gradually melting the snow. Often Mrs.
Bear's home is discovered by means of the tiny hole in the roof around
which is collected quantities of hoar frost.

Hibernation is one of the strangest phenomena of the animal world, and
bears, especially the white bear of the polar regions, the black bear of
North America, and the brown bear of Europe, agree in the curious habit
of semi-hibernation. In the late fall of the season, the bears begin to
eat heavily and soon become enormously fat, preparatory for the long
winter of semi-sleep.

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 metamo