Grebes are expert swimmers and divers. Before the invention of smokeless powder, the adult birds could easily dive at the flash of a gun and were beneath the surface of the water when the shot struck. On land these duck-like birds push themselves over the ground on their breasts, or waddle along in a very awkward manner. They cannot rise from the ground, and even when rising from the water they must flutter over its surface for a long distance before they are able actually to take wing. October Twenty-sixth A strong aversion for snakes prevails with many of us. Most people think that the majority of snakes are poisonous. In reality the only dangerously venomous snakes in the United States are the rattlesnakes (fourteen species), the moccasin, and the copperhead, and they are not so aggressive as is generally supposed. October Twenty-seventh How often the osprey or American fish-hawk is mistaken for an eagle! The fish-hawk is the only hawk that will poise in the air and then plunge into the water for its prey. Unlike the kingfisher, of which of course it is no kin, it carries its food in its talons instead of in its beak. In captivity it may be confined in an aviary with pigeons, quail, and other defenceless birds, and will not molest them. [Illustration: HORNED GREBE. Winter Plumage.] Notes October Twenty-eighth The bull-frog, whose legs are considered such a delicacy, often attains a length of fifteen inches. Its food consists of insects, small frogs, birds, mice, and young water-fowl, and one has been killed which had eaten a bat. Birds have learned to look upon it as a foe. Bull-frogs are fast becoming extinct because of the demand for their legs. October Twenty-ninth The sharp-shinned hawk is smaller in body, but has about the same expanse of wing, as a domesticated pigeon. It is one of the few hawks that is destructive to birds and young poultry. Not only in the country, but in the city parks and villages, it is seen in late fall or in winter, skimming over the tops of the bushes ready to pounce upon a sparrow of any species the instant one appears. October Thirtieth Red squirrels and chipmunks differ in size, markings, and habits. The red squirrel is nearly twice as large as the chipmunk, it nests in trees, and is usually seen among the branches. It is red on the back and whitish beneath, sometimes having one black line along each side. Chipmunks live in the ground, hollow stumps, and roots. They are poor tree climbers and will not jump from tree to tree unless forced to do so. They have a black stripe down the back and two on each side. [Illustration: SPOTTED SANDPIPER.] Notes October Thirty-first At dusk or early in the evening the weird, tremulous wail of the screech owl may be heard. Sometimes one will visit a favorite tree at the same hour evening after evening, and after sounding his cry several times, will glide away into the country to hunt for a supper of beetles, meadow mice or white-footed mice.