Why do some animals have tails?

Animals have tails for various purposes, including balance, communication, and defence. Cats and kangaroos use their tails for balance during movement, while monkeys use prehensile tails to grasp branches. Tails can also signal emotions or warnings, as seen in dogs or rattlesnakes. Some animals, like lizards, can detach their tails to distract predators, demonstrating the tail’s critical role in survival.