The evolution of itching is believed to have helped humans survive by prompting the removal of dangerous insects or parasites that could transmit diseases. Itching isn't unique to humans; it's even observed in fish, who rub against rocks to scratch.
Itching is a survival mechanism against disease-carrying insects.
Itching behavior is seen across the animal kingdom, including in fish.
It was only in the last few decades that science became aware that itches aren't just low-level pain. And in that time, the mystery of how we itch and why we scratch has gotten even more baffling. Explore the mystery with Josh and Chuck in this classic episode.