on the bright side,I'm not exhausted trying to keep up with the usual hyperactive young rat personas

I'm starting to think my new rats aren't particularly fearful of the outside, but just really phlegmatic for their age. I keep the cage open for hours on end every evening and they don't venture out. I set them outside and they run back inside again (mostly to sleep some more). And I don't hear them tearing around the cage at all hours like maniacs, scuffling and making a racket either. I'd worry that something was wrong with them, but their appetite is good, their fur is glossy, and they are growing as you expect. And they react quickly enough to the treat noise. They just seem lazy. I mean, not that I can't relate, but seriously. They don't even use half their cage regularly, content to hang out in just the upper part.

Well, maybe they'll grow up into lap rats who hold still for petting and cuddling. I mean, when I took Silas outside today, sat down on the floor near the cage ramp, and petted him while he sat on me, he just kept sitting for quite a while before he decided to bother running back up into the cage. But I did not equip the room with a ferret climbing tree, two tree branches, a box for digging, tunnels etc. just to trip over rat stuff. This is really odd.