I personally wouldn't use any rat that bites in a persevering breeding program. That said, I don't see anything wrong with using them and feeding off the babies (as long as you are Ok worth the possibility of getting bit again), I just wouldn't keep ANY babies from them . Future breeders. There are enough well tempered rats out there, it isn't worth it. Biting is just unacceptable, unforgivable behavior IMO. And a serious bite is no joke. I was bit on my right index finger when I stuck my hand between two squabbling rats. I still have a scar, and this was 5+ years ago. Within a half hour my finger had swelled up to 3 times it's normal size, and by the time I could see the doctor it was starting to turn blue and gray. Not exaggerating. The doctor said that was a normal reaction. Apparently there is something on the surface of rat teeth that most people react to. She updated my tetanus, prescribed preventative antibiotics, took an xray to make sure a tooth didn't break (didn't), and sent me on my way. It took me weeks before I could use that finger again, and months to heal fully. Since then, I have NEVER tolerated any kind of the slightest aggression. That was a pet/show rat too, not something that was mistreated.