Some internal force which is irresistible compels it to seek twigs and weave them into a nest. The bird has no time to stop and think what it is doing, nor does it wish to, for it enjoys nest building. It is, of course, impossible for a human being to understand the frame of mind of a bird when building its first nest. The only approach to it that we ever experience is when we are suddenly seized with an impulse to do something unusual, and we obey the impulse and are afterwards surprised at ourselves.
There is a story told of a wealthy man who had been out hunting and was returning home tired and thirsty. He dismounted at a farm-house, went inside and asked for a drink. While this was being obtained he noticed a lot of valuable old china on the dresser: seized by a sudden impulse, he knocked it all down, piece by piece, with his riding whip. His hostess on her return with the drink looked surprised. The hunting man smiled, asked her to name the value she set on the china, sat down and, there and then, wrote out a cheque for the amount.
It always seems to me that when a bird begins for the first time to collect materials for a nest she must act impulsively, without thinking what she is doing. Just as the hunting man was seized with a sudden desire to smash the crockery with his whip, so is she suddenly impelled to collect twigs and build a nest.
Another instinctive act which is apparently purposeful is the feigning of injury by a parent bird when an enemy approaches its young. Superficial observation of this action leads the observer to imagine that the mother bird behaves thus with deliberate intent to deceive, that in so doing she consciously endeavours to distract attention while her young ones are betaking themselves to cover. As a matter of fact, the bird will behave in precisely the same way if she have eggs instead of young ones. This has, of course, the effect of drawing attention to the eggs, and proves that the action is instinctive and not the result of reasoning.
Most people have remarked the cautious manner in which many birds approach the nest when they are aware that they are being watched. This has the appearance of a highly intelligent act. It is, however, nothing of the kind.
