I wouldn't worry too much at this point. From reading all the posts you can tell that it happens with most all of us!! The worse ones seem to happen at night and I think it is because they sleep all day and look for trouble at night! None of mine have ever really harmed each other and sometimes I think it is play that goes sour. Somebody got a little rough and then somebody decided to get even, and now everybody is mad and the fur is flying!!! Everything is fine when the sun comes up! (Most of the time!!)