Why do tarantulas have such hairy bodies?

Tarantulas are covered with sensory hairs that detect air movement, vibration and touch, helping them navigate and hunt in low-light conditions. In many New World species, the abdomen carries urticating hairs that can be flicked at predators, causing irritation to eyes and skin. These hairs are a defensive adaptation rather than simple body covering. Tarantulas belong to a large and ancient group of spiders, and their size and hairiness often make them seem more dangerous than they usually are to humans. Their sensory equipment is vital because they rely heavily on vibration rather than sharp vision.