If you’re walking through a rainforest, you might want to keep your head up. How else would you know to duck to avoid a swinging gibbon? Gibbons are playful and fun apes who live in the treetops.

When people think of primates, they often picture playful monkeys, intelligent apes, or even cuddly zoo animals. Pop culture paints them as adorable, clever, and harmless. However, this oversimplified ...