BIRDS THAT LIVE IN NESTING BOXES. Certain varieties of birds will nest in homes built for them if these houses are of the right shape and dimensions. Other birds may be just as desirable but do not build nests and rear their young in boy-made nesting boxes. We are therefore mainly concerned with the first group which select cavities in trees for their homes if nothing better is to be found. FIG. 1. BLUE BIRDS, ADULTS AND YOUNG BIRD. BLUEBIRD.... more...