The smaller forms,[2] generally called "cottontail rabbits," occur in every State, but are absent from the greater part of Maine, the northern parts of New Hampshire, Vermont, New York, Michigan, Wisconsin, and Minnesota, and from the western parts of Washington and Oregon. In recent years they have extended their range northward in the New England States, New York, and portions of the West, and have invaded and occupied a considerable part of the Province of Ontario. In habits they differ materially from the larger rabbits. They live in copses and thickets more than in open fields. The young are born blind, naked, and helpless, while those of the larger rabbits have the eyes open, are partially furred, and active when born. [Footnote 2: Genus _Sylvilagus_.] Rabbits of both genera, however, feed exclusively on vegetation, and are at times harmful to crops and especially to trees. Because of their size and great abundance in parts of their range, jack rabbits are by far the most destructive, but, except in a few places where they have been introduced, none are found east of the Mississippi. Epizootics (diseases which attack many animals at the same time) are an effectual natural check, and after such attack occurs, jack rabbits are usually so reduced in numbers that they are not troublesome again for several years. Traps and other devices that are effective with cottontail rabbits do not always succeed with jack rabbits. The recommendations contained in this bulletin will, therefore, apply only to cottontail rabbits, but they may suggest methods that, with modifications, may be used against the larger forms. HABITS OF COTTONTAIL RABBITS. Cottontail rabbits (fig. 1) are so well known that little need be said of their habits. They breed several times each year during the warmer months, the litters averaging five or six young. The nest is usually placed in a hollow or depression of the ground, often in open fields or meadows. It is composed of dead grass and warmly lined with fur which the female pulls from her own body. The male rabbit takes no part in caring for the young, and the female weans them as soon as they are able to leave the nest. These animals breed so rapidly that in spite of many natural enemies, and of the fact that they are hunted for human food, they often become numerous enough to inflict serious losses on farmers and fruit growers in many parts of the United States (fig. 2).