system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do cats always lift their butts and their tails way up in the air when you scratch them right in front of the base of their tale?

They also get really really excited.

Edit: I am having a hard time imagining how you would scratch a tale, unless that would mean slang for rapping to your cat. I meant tail, not dropping sick beats on them.
gpt
It's an instinct that comes from kittenhood, specifically grooming. When a mother is licking clean her kittens, raising the backside of their body allows greater access to that part of the body from the mother's tongue.