"We cannot tell exactly. It is something which God has given to animals to teach them what is best for themselves and their young. It is not reason, for they have no soul nor mind as men, women, and children have; but by it some animals, such as dogs and horses, often seem to know what is right and wrong. It is instinct which teaches the bird to build her nest. I am an old man, and I suppose you think I know a great deal, but if I wanted to build a house for my children, I would not know how to do it unless I were shown. But little birdie, untaught by any one,--led only by the instinct which God has given her,--makes her nest soft and comfortable for her young. It is instinct which teaches Toby to know a man or a boy who is to be trusted from one who is not; which makes him keep Susie from creeping into danger when he is told to take care of her."