_Some Useful Birds._--Most people who have made the acquaintance of our common birds know the friendly little Chickadee, which winter and summer is a constant resident in groves of deciduous trees. It feeds, among other things, on borers living in the bark of trees, on plant lice which suck the sap, on caterpillars which consume the leaves, and on codling worms which destroy fruit. One naturalist found that four Chickadees had eaten one hundred and five female cankerworm moths. With scalpel, tweezers, and microscope these moths were examined, {106} and each was found to contain on an average one hundred and eighty-five eggs. This gives a total of nearly twenty thousand cankerworm moth eggs destroyed by four birds in a few minutes. The Chickadee is very fond of the eggs of this moth and hunts them assiduously during the four weeks of the summer when the moths are laying them. The Nighthawk, which feeds mainly in the evening, and which is equally at home in the pine barrens of Florida, the prairies of Dakota, or the upper air of New York City, is a slaughterer of insects of many kinds. A Government agent collected one, in the stomach of which were the remains of thirty-four May beetles, the larvae of which are the white grubs well known to farmers on account of their destruction of potatoes and other vegetables. Several stomachs have been found to contain fifty or more different kinds of insects, and the number of individuals in some cases run into the thousands. Nighthawks also eat grasshoppers, potato-beetles, cucumber-beetles, boll-weevils, leaf-hoppers, and numerous gnats and {107} mosquitoes. Surely this splendid representative of the Goatsucker family deserves the gratitude of all American citizens. Among the branches of certain of our fruit trees we sometimes see large webs which have been made by the tent caterpillars. An invading host seems to have pitched its tents among the boughs on all sides. If undisturbed these caterpillars strip the foliage from the trees. Fortunately there is a bird which is very fond of these hairy intruders. This is the Cuckoo, and he eats so many that his stomach actually becomes lined with a thick coating of hairs from their woolly bodies. The Baltimore Oriole also is fond of rifling these webs.