system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: if picking at scabs and zits is bad, what explains the irresistible urge to do it?
gpt
The reason we have such a nagging urge is because our skin's nerves tell our brain that something is attached to us. The brain interprets this stimuli and responds by urging our hand to scratch it or get it off. The benefit to this response is that potentially harmful parasites or insects can latch on to our skin and transmit disease, so it's better to be safe than sorry.