M.H.
I have an inhome day care and have been through this myself a few times. My daughter (2 yrs old) has bitten 4 times, but we were also moving from our house to a rent house for 2 months and then into our new home. Frustration can play a big part of why kids bite. If they don't get allot of sleep at night they are more cranky the next day and specialy at this age they don't understand how to share yet. If they see someone playing with a toy they had 10 mins ago they still think it is their toy. With my daughter, I make her go to the child that she has hurt, she has to tell that child that she is sorry and give them a hug. Then she has to sit in time out for a few mins while that child gets to play with the toys that caused the biting. I will always call the parents if it is a bleeding bite mark. One thing that I have learned to do is to tell them their child got hurt, but I am taking care of the situation and tell them how it happened and what I did to correct the children involved. If my daughter is awake when that child goes home, I will have my daughter tell the parent of the child she has hurt, that she is sorry and I make her tell them why she is sorry. Some parents specialy first time parents don't understand why children bite. Having my daughter say she is sorry allows me a chance to tell the parents that my daughter is not a mean child. Something just happened between the two kids that caused it. I've seen one of the boys that I take care of go up and take a book out of my daughters hand and take off with it. She went up to him to get it back, but he would not let go, so she leaned over and bit his hand. I wasn't sure how to dicipline the kids. I told my daughter that we do not bite our friends even if they take our toys. She said she was sorry and was sent to time out. After calming the little boy down, I had to tell him it's not nice to take things away from our friends. I felt bad for my daughter because she was in time out but he wasn't. I have started putting him in time out as he has gotten older.
A great tip for any kind of bruise, scratch, bite... rub some vasaleen on the mark. It helps the mark to not turn blue. It works great!