Tuna may be the chicken of the sea, but octopi, lobsters and crabs are the hens. That is, the females of each those species is called a hen. Aaron Zenz’s lovely book for children I Love Ewe: An Ode to Animal Moms offers a little lesson about female names in the animal kingdom. He does the same for the males of the species in Hug a Bull: An Ode to Animal Dads. This is part of a complete episode.