system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does it feel so good to itch a scar/insect bite? Is there a genuine medical advantage to it?
gpt
It has more to do with the itch being a signal from your body asking for attention. A bug bite or irritation would require you to bring your attention to that area of your body to remove the irritation. The itch signals a need and once you scratch it,  you feel a relief that acts as a reward encouraging you to continue to bring your attention to irritations.   
  
Consider it less an advantage feeling the relief post-scratch and more of an advantage to have a signal system that causes the irritation in the first place.