Cat lick spots

Many of my friends’ cats have a peculiar behavior that I was hoping someone here might be able to explain for me. I googled all around and couldn’t find anything…

When you scratch their back just at the base of their tail, they begin wildly, uncontrollably licking themselves. As soon as you stop scratching, so do they.

Any clues as to what might trigger this behavior?

I asked a veterinarian about this, and he said that there is a nexus of nerves in that area. Stimulating this nexus by rubbing can trigger an automatic response of licking that is related to grooming behavior.

It’s strange to see a cat licking thin air. Some of them will lick the nearest thing, like your hand, but some just lick nothing. They often get a glassy-eyed, stoned look, so I think they enjoy it.

Thank you! It’s been plaguing me!