Some fossils give us information about how adults took care of their young.

These are nests of two different types of dinosaurs.

Paleontologists found broken egg shells and the bones of young dinosaurs in the nests of this dinosaur, Maiasaura.

By comparing this with nests of living animals, scientists infer that the baby dinosaurs stayed in the nest after hatching and were cared for by their parents, just like some birds.