Do nits bite?

I had lice when I was like 8 and I know quite a lot about them. I kinda found it interesting that bugs were living on my head. Anyway, yes they do bite they eat your scalp. that causes sores that itch. That why your head itches when you have lice.

Another answer:
Actually nits don't bite, lice do. Nits are the eggs, and some authors limit the definition to dead lice eggs. So the eggs are either hatched already or incapable of hatching. That makes things confusing when schools have "no nit" policies, and only nymphs and adult lice spread. Abandoned egg shells and dead eggs (often after using lice shampoo) cannot spread nor bite. However, there is no way of knowing by appearance whether the eggs are viable or not.