For some reason best known to themselves wrens and bluebirds dislike to raise a second brood in the same nest, and as these birds raise two broods each year, several nests should be provided if we wish to have the family remain with us. Most birds are naturally quarrelsome and it is always best to provide lots of houses.

It is a common error to make bird houses too ornamental, with the result that they fail to harmonize with their surroundings - a serious defect in the opinion of most birds. The inherent idea of self preservation usually results in the selection of quarters as unobtrusive as possible, and it is for this reason that a bird house made from an old log is so often found tenanted.