Then the baby pokes and stretches and struggles, with rest stops in between, until it breaks free of the shell. Eggs usually hatch a day apart in the order they were laid. Photo courtesy of Jim Gilbert. We have been watching the female fly off to collect nesting material. She has built 2 nests within 5 feet of each other.
Animals have a hard time resisting supernormal stimuli.
Most people, including people who study robins, have never seen this happen. Last time we talked about worms, a favorite robin food. Many people wonder how robins find the worms. Most scientists now conclude that robins find worms by vision, thanks to experiments by an ornithologist named Frank Heppner. In his experiments, Heppner investigated all the robin's senses.