Parents need to know that The Croods, while quite funny and gorgeously animated, deals with some pretty heavy themes: the constant risk of death and worries about the end of the world. Prehistoric times are convincingly wild, dangerous, and unstable: Rocks fall, mountains tumble, and the Earth opens up and swallows the ground whole (all made even more immediate when seen in 3-D). The frequent peril and talk of the end of the world are likely to make younger kids nervous. And then there are the conversations about parents dying and kids themselves being in danger; at one point, viewers may even think a central character has perished. Other scenes show characters battling other creatures for supremacy and food, so there's plenty of slapsticky whacking and hitting, too. Female characters do end up getting saved by males, and you may find yourself heading to the Internet to research the accuracy of the movie's creatures and events. All of that said, The Croods has a wonderful message of courage and celebration of adventure at its core, and there are strong, loving family relationships.