Though the Bear is classed with the Carnivora, or flesh-eating animals, it is really omnivorous in the best acceptance of that word, for it will thrive on a vegetable diet for many weeks at a time. Bears will devour the various kinds of berries, grains, the succulent leaves of herbs and the fleshy roots, with evident relish. There is, perhaps, no more dainty morsel for them than the young and tender buds of trees and shrubs as they are prepared by Nature, wrapped in their winter covering and containing an abundant food, stored there for the nourishment of the growth of the coming season — a food useful to the animal as well as the plant. The young seem to depend entirely on vegetable food, but as they grow older, though still preferring the products of the plant, they will eat a variety of animal forms, such as insects, mollusks, crustaceans, worms, birds and their eggs. When driven by hunger they will kill and eat larger prey, such as deer and domestic cattle. They will also devour the dead bodies of animals freshly killed, but only before there is any taint or odor. Thus, though Bears have the structural characteristics of the flesh-eating animals, this classification is misleading to the untutored observer who watches them in our menageries or even in their native homes.

The Polar Bears are perhaps the most carnivorous of them all, living almost entirely on animal food, when in their natural homes. The Grizzly Bear is also a flesh-eating species, though it will subsist on a vegetable diet. It is an interesting fact that the nature of their food seems to determine the degree of strength and the ferocity that they possess. The influence of the diet is shown not only on the various species but also upon the individuals of the same species. The Bears fed only upon vegetable foods exhibit a much milder disposition and are less resentful when crossed.

Bears are distributed throughout the world except in Australia. In the words of Brehm, "They inhabit the warmest as well as the coldest of countries, high mountains as well as the coasts of the Arctic Sea. Nearly all species select dense, extensive forests or rocky regions, generally lonely spots. Some delight in watery or damp situations, streams, rivers, lakes, swamps and the sea, while others prefer stretches of dry land. One species is confined to the sea coast and seldom penetrates the depths of the continent, but still undertakes more extensive migrations than the others, traversing great distances on drift ice, crossing the northern Arctic Ocean and migrating from one continent to the other."

Besides the bears of the present day there are extinct forms, remains of which occur in the later geologic ages. The Great Cave Bear, remains of which have been found in the caves of Central Europe, indicate that this species was even larger than our Polar Bear, which may measure nine feet in length.

The opinion is prevalent that the movements of the Bear are awkward and slow and that they are neither fleet nor active in locomotion. This is true, to a certain extent, in the case of the larger species, though they are endowed with great endurance. On the other hand the smaller species are notably quick and active in their motions. In fact all species when excited will pass over the ground at a rapid rate, their strides resembling a sort of gallop. All climb, especially when young or until their great weight prevents them from doing so.

A few of the species are excellent swimmers and can remain under water for some time. The Polar Bear well illustrates this characteristic, for it has been seen many miles from the shore, swimming easily and showing a wonderful power of endurance.