Are we suppose to respond to insect bites? I know we are supposed to be non responsive but what if it is going to cause physical harm?

The question is not.
What do you mean by response? Killing the insect or treating what it has done to the body?
If it is treating then, yes!
We should respond to the bite and treat it.
If is killing the insect, it depends. If the insects is a a threat or a nuisance such as fleas or mosquitoes then, Yes! For the sake of others and yourself.