In the southern part of the country the Carolina chickadee[9] and the tufted tit[10] replace the black-cap, but their food habits are so similar that there is practically no difference in the work done. In the West several other species occur; one of the most interesting is the bush tit[11] which, with several subspecies, occupies the whole Pacific coast region. They are active, social little creatures, and except for a short time during the breeding season are found in flocks, flitting from tree to tree, busily hunting for insects and their eggs The contents of 66 stomachs of these birds were found to consist mostly of injurious insects to the extent of 83 per cent. Of these the most important was a small hemipterous insect which amounted to more than half of the stomach contents. These insects are of considerable economic importance, as they frequently infest grapevines and other plants to a harmful extent. Several stomachs were almost exclusively filled with these minute creatures, some containing as many as 100 individuals. [9] _Penthestes carolinensis._ [10] _Bæolophus bicolor._ [11] _Psaltriparus minimus._ Perhaps the most important and interesting insect found was the black olive scale, which occurred in 24 stomachs and amounted to a little more than 18 per cent of the food. In addition a number of the stomachs were more or less filled with another scale, which was not further identified. A number of small snout beetles (weevils) were eaten and some small caterpillars; there were also the remains of a spider. The vegetable food of the species seemed to consist mostly of seeds, but they were so broken up as to defy recognition. A little fruit pulp and a little mast were also found. Among the stomachs of the bush tits examined were those of one brood of eight nestlings about 10 days old. The vegetable matter in these stomachs was only three-fourths of 1 per cent and consisted of one seed and some rubbish. The animal matter was made up of beetles, wasps, bugs, caterpillars and pupæ, and spiders. The greatest interest lies in the fact that every one of these stomachs contained pupæ of the codling moth, on an average of over five to each. The oak tree in which these birds were found was in a belt of timber near a neglected orchard which the parent birds used as a foraging ground, and they did their best to remedy the neglect of the owner. As feeding and digestion in the case of nestling birds is almost continuous during the hours of daylight, the above record would be several times repeated during a day’s feeding. There were probably not less than a dozen nests of the bush tit along the border of this orchard, and these birds must have exerted a great restrictive influence upon the increase of the codling moth, as well as of other insects in that vicinity. THE WRENS. [Illustration: Fig. 4.—House wren. Length, about 4¾ inches.]