With mouths agape from ear to ear, the swifts draw in an insect dinner piecemeal, as they course through the air, just as the whip-poor-will, nighthawk and swallows do. {183} Fortunate the house where a colony elect to live, for they rid the air of myriads of gnats and mosquitoes, as they fly about overhead, silhouetted against the sky. Early in the morning and late in the afternoon are their hours for exercise. You will think, perhaps, that they look more like bats than birds. Watch their rapid wing-beats very closely and see if you can settle the mooted question as to whether they use both wings at once, or first one wing and then the other in alternate strokes. After you have noticed their peculiar, throbbing flight, you will never again confuse them with the graceful, gliding swallows. Although the swift is actually shorter than a sparrow, its spread wings measure over a foot across from tip to tip. No wonder it can fly every waking moment without feeling tired, and journey from Labrador to Central America for a winter holiday. RUBY-THROATED HUMMINGBIRD What child does not know the hummingbird, the jewelled midget that flashes through the garden, poises before a flower as if suspended in the air by magic, thrusts a needle-like bill into one cup of nectar after another, then whirs off out of sight in a trice? It is the smallest {184} bird we have. Suppose a fairy wished to pluck one for her dinner, as we should pluck a chicken; how large, do you think, would be the actual body of a hummingbird, without its feathers? Not much, if any, larger than a big bumble-bee, I venture to guess. Yet this atom of animation travels from Panama to Quebec or beyond, and back again every year of its brief life, that it may live where flowers, and the minute insects that infest them, will furnish drink and meat the year around. So small a speck of a traveller cannot be seen in the sky by an enemy with the sharpest of eyes. Space quickly swallows it. A second after it has left your garden it will be out of sight. This mite of a migrant has plenty of stay-at-home relatives in the tropics--exquisite creatures they are--but the ruby-throat is the only hummingbird bold enough to venture into the eastern United States and Canada.