After seeing it. I'm guessing it's a baby guinea pig? It's probably the size of a medium rat. He's pretty frightened right now, and doesn't want to be messed with. But, I don't think it comes close to a gerbil or hamster. Thoughts?
It has more of an elongated face than a rodent. And the poor thing is skin and bones.HE's eating well though, and seems to be alert.