That's what I am thinking. But he has been fed live for 3-3.5 years by previous owner. Are rats aggressive? I always watch him as he eats but I don't want it to hurt him.
Mine gets two mice per week and would be the appropriate size to take a small rat, there's just nowhere near where we live that sells anything other than large feeder rats.
Just have something like tongs or a pencil or something on hand to put in the rat's mouth if it starts trying to bite.