system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why won't the human body build up a resistance toward insect bites such as fleas or gnats?
gpt
When something gets inflamed on your body, like at the site of a bug bite.  That's not the bug's doing.  That's your immune system's reaction to the bite.  Keeping you safe from whatever the bug's mouth brought with it as best it can.  We can't build up a resistance to that, because that reaction you get that's the body resisting.