The character of the food of titmice gives a peculiar value to their services, for it consists largely of the small insects and their eggs that wholly escape the search of larger birds. Throughout the year most of the species of this group remain on their range, so that they are constantly engaged in their beneficial work, continuing it in winter when the majority of their coworkers have sought a milder clime. It is at this season that the titmice do their greatest good, for when flying and crawling insects are no more to be found, the birds must feed upon such species as they find hibernating in crevices, or upon the eggs of insects laid in similar places. In winter's dearth of moving insects the search for such animal food as may be found is perforce thorough and unremitting. Within the boundaries of the United States are some 17 species of titmice, with nearly as many races or subspecies, so that there is no portion of the country lacking one or more forms. The western coast region is peculiarly rich In representatives of the family. In the eastern portion of the country the best-known and most widely distributed species is the common black-capped chickadee[8] (fig. 3). This bird, or some of its subspecies, occupies the whole of that part of the United States north of the latitude of Washington and extends into Canada. It is a prolific breeder, usually rearing from six to eight young in a brood. [8] _Penthestes atricapillus_. [Illustration: Fig. 3.--Black-capped chickadee. Length, about 5¼ inches.]