Rabbits may bite for several reasons. The can do it to get attention. They can do it to communicate distrust or as a defensive action. You have to look at it in context. A bunny may bite to say: Hey, pet me! Or Get me a treat! To a person that’s idiotic and if a dog would do such a thing, you’d have to have it put down most likely. But in a bunny it seems like it’s a perfectly normal way to get the bunny point of view across. The darling biter may even look totally surprised when you seem to take offense.
Defensive, scared bites are usually more severe.
If squealing helps, that’s great, then it’s probably “attention-bites”. Half-hearted defensive bites can go away with time. My Yohio could bite me for almost a year but less and less, now he’s stopped. If I don’t get up out of bed and give him breakfast when breakfast is over-due, he may still try a tiny little nibble just to get me moving though (we sleep in the same bed).