I'm having the same issue in my home right now. Hercules is almost 7 months and we just got Athena last week, she's 9 weeks. They seem to play soo rough together, but I hardly ever hear a yelp. I usually let them play. If they are in pain, they will let us know. I'll separate them every now and then if I think they might need a break for water, or something like that. Otherwise I'll just let them wear each other out!
__________________ Brandi, Hercules, & Athena  |