system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we pick scabs?
gpt
For the same reason we might mindlessly pick at some dried glue on our hand--our subconscious mind sees it as something foreign that doesn't belong on our body. Of course, scabs are part of us (at least temporarily), and they're critical for wound healing, which is why the picking stops when our conscious mind kicks in. But it isn't entirely in our heads: The presence of histamines in scabs can make them feel itchy.