Martins have been known, when no house was provided for them, to take possession of part of a pigeon house; and no pigeon ever dares to set its foot in the martin's side of the house. The martin is a very courageous and spirited bird, and will attack hawks, crows, and even great bald eagles; he whirls around and around them, and torments them, till, at last, he succeeds in driving them off. This makes the martin a very valuable friend to the farmer, whose chickens he defends from their enemies.