How do animals experience pain?

Humans know the surprising prick of a needle, the searing pain of a stubbed toe, and the throbbing of a toothache. We can identify many types of pain and have multiple ways of treating it — but what about other species? How do the animals all around us experience pain? Robyn J. Crook examines pain in both vertebrate and invertebrate animals. [Directed by Anton Bogaty, narrated by Julianna Zarzycki].