The animal known for living in trees and possessing a long tail is the monkey. Monkeys are primarily arboreal creatures, meaning they spend most of their lives in trees. They belong to the primate family and have adaptations such as strong limbs and gripping tails that help them navigate their forested habitats. Various species of monkeys, like howler monkeys and capuchins, can be found in tropical regions around the world. Their social structures and playful behaviors make them fascinating to observe, both in the wild and in captivity, contributing to their popularity in wildlife documentaries and zoos.