system
Given the following post, respond as if you're commenting on Reddit:
human
Actual ELI5: If dogs have such a good sense of smell, why do they stick their noses up our butts?
gpt
Dogs have a scent gland in their behinds that can tell a lot about a dog. It can tell the sex, their general health and the dog's temperament. So, it's instinctual for a dog to smell another dog's behind. This extends to humans because we're part of their pack.