I lost a breeder male and I put in a new young male rat. He immediately grabbed a pinkie up and mauled it. I removed him back to a bin without babies.

Now... is he aggressive and I need to feed him off? Was it because they weren't HIS pinkies? Was it because he's young(although he's well big enough to be a breeder, about 250 grams guessing)?

At this point, I'm planning on using him for a feeder rat. I have no desire to breed aggressive or "murderous" rats. Am I right in this? I've never dealt with a MALE killing babies. And he wasn't accidentally injuring one, he grabbed it and bit it repeatedly. Females that kill litters for no reason are fed off, but a male? Normal? Bizarre? Snake food?

Thanks in advance for any advice.