Sticklebacks near their nest

In spring the male threespined stickleback builds a nest for eggs. After that he picks female sticklebacks to visit the nest and deposit eggs. Once eggs have been laid, the male guards the nest, repairs and cleans it, and aerates the eggs. When baby fish appear, the father dismantles the roof of the nest turning it into a cradle. He takes care of his offspring after eggs hatch, but eventually loses interest in them and can even eat some of his children forgetting who they are.