<human>: Can you summarize the given text in a few sentences?

I adopted a couple lab/catahoula pups a week ago (they're 9~ weeks old now) and they're very sweet and lovable but they play a bit too rough. I understand pups are going to wrestle, jump and bite on each other, but it seems like they're doing it too hard. 

Usually (from what I've seen/read) pups/dogs will play and when one of them gets hurt, they'll yelp and the other dog will stop/get off. But these 2 will bite each other and even if the other one yelps, they keep biting until I yell or pull them off. They don't avoid each other and even sleep in the same bed just about every night. They just don't seem to know when enough is enough. I'm afraid that I'll come home to one of them bleeding.
<bot>: the pups will bite each other hard, and keep biting even if the other one yelps. Do I have a cause for concern? If so, how should I get them to understand that playing shouldn't hurt?