The hummingbird is a family of New World birds. About 400 species are found in the two Americas, ranging from Alaska to Patagonia. There are eight species on the Mexican border. The name comes from the insect-like rapidity with which they move their humming wings. The motion of the wings is so rapid, in fact, that the bird is able to hover stationary, without perching, while it probes with its long bill for nectar or gathers insects. Only one species, the ruby-throated, is found east of the Mississippi. It is a beautiful little fellow, the length of one's forefinger, with bright, shining, green upperparts, a ruby red throat, and purplish wings and tail. Two white eggs, half an inch in length, are placed in a tiny nest of plant down saddled on a limb fifteen to twenty-five feet from the ground. The outside of the nest is covered with lichens to make it look like a knot. The hummingbird feeds chiefly on insects caught on the wing or picked from flowers. The hummingbird's tongue is double nearly from end to end; so that the little bird is able to grasp its insect prey with its tongue, much as if its mouth were furnished with a pair of fingers. It is fond of plant sweets. The female bird feeds her young, at first not much larger than bluebottle flies, by thrusting her bill down their throats and ejecting a quantity of prepared food, chiefly minute insects, from her own store-house.