Lola, who is 3 months is getting very physical with Gracie ( 1 year old) now. She is beginning to play much more rough...nipping, jumping and all that fun stuff. The problem is that Gracie puts up with ALOT, but she is starting to nip back at Lola. Lola lets out a big "ouch yelp". I don't think Gracie is nipping very hard...I think Lola makes alot more noise. Sometimes Gracie tries to grab her leg..which is why I never let them play unsupervised...so I guess my question is how much do I allow before I break it up or do I allow it at all. It starts out as play , but I am afraid Lola is going to get hurt.