I’ve had 4 male gerbils (Father and his 3 pups) living together For nearly 2 years. Then about an hour ago, I noticed the father gerbil fighting one of his pups. I intervened luckily before it got to bloody, but they both of their mouth and upper chest areas seem to be covered in blood. I cant seem to find any wounds that are visibly leaking blood on either of them. But after i separated them it doesn’t seem like they are able to chew anything anymore and their mouths both kinda look damaged. When i separated them i put the pup that was fighting and one of his brothers in a cage and left one with the father. Is it common for them to have damage to their mouths after fights? The father gerbil tried to chew a sun flower seed and he couldn’t even brake it open.