The goose is engaging in a Fixed Action Pattern. This is an evolutionarily advantageous tactic that causes an animal to automatically complete a certain task. In this case, it is advantageous for the goose to bring things that leave the nest back in. This causes the goose to instinctively do so.
Work Step by Step
The goose example is often used to demonstrate a Fixed Action Pattern. Since the goose does the same action for a situation in which the action makes sense and one that it doesn't, it is a Fixed Action Pattern.