Disagree completely on this being "normal" behavior for this age. I come from a large family and to my knowledge only one of the g'kids was a biter and he was the "aggressive" one and the other cousins were actually afraid of him until one of them (same age) bit him back hard - then HE did the crying, and we all told him THAT's what it feels like when you bite people, and from then on he quit because he realized the others in the play group would not tolerate it, nor the adults involved. By the way, an adult "biting" just to show a little discomfort to the "bitee" does not cause "marks" and is NOT abusive. I do not work at a daycare facility, but I know an owner of a very well known one and it's not something they see in very many kids and they tell the parents to deal with it or they are not welcome to continue bringing them there, because THEY could be liable to lawsuits if another child is hurt bad in their care if they know there is a problem and they haven't dealt with it. Would you like your child to be the innocent victim? Some bites can get infected and be quite dangerous.
No one said it was "common." It's not. I'd say it's less than 5% of my kids who have ever bitten. But, It DOES NOT mean there is anything wrong with the child or their parent's methods of discipline.
When you work in child care, you see many "types" of children and none of those types fit all the kids, but all of those types are NORMAL.
Of course, NO ONE likes it when their child is bitten. No day care provider LIKES being the adult present when these things happen. But, we have compassion for both children. They are very young, we're not talking about grade schoolers here. You have to take into account their inherent immaturity. They do not know what they are doing.
Yes, sometimes day cares have to discontinue care if they can't make a breakthrough with a particular child. You create a plan of action; but if it isn't working, a new environment may be just what the child needs. I've actually had two children brought into my day care after biting at other facilities. They didn't bite once here. I knew to be on the lookout, but the change in environment did the job for me.
And, it's nearly impossible for Parents to correct biting without the assistance of day care. Very often, day care is the place biting takes places the most. A number of reasons:
1. Due to their age, very often, there are no smaller children at home. There are ample smaller children at day care.
2. They are in their comfort zone at home. (Even when they've been in day care for years, it's still not home. Kids behave differently.)
3. Older siblings and parents generally do not cause the same level of frustration as other small children who do not know how to treat this child in order to prevent biting. They are all learning social skills. There will be more incidents under these circumstances, and some of those result in biting.
4. They spend more waking hours at day care than at home during the week. It's fairly likely you'll have more incidents there. So, the day care has to take an active part in dealing with these issues. You can't just expect parents to "fix it." That's just not feasible without the help of the day care.
Obviously, no one wants their child to be the victim. That's a given. But I've seen the parents of biters get just as upset as the parents of the bitees. They DO care about the children who are being hurt and are not happy that their child is the aggressor. This is very stressful for parents and these attitudes that they have done something wrong and should just "fix it" do not help in any meaningful way. It just adds to the stress around the child and can aggrevate the situation. A calm, measured approach is much more successful.