Yesterday, Wheatley's cage was pretty barebones: I pretty much added a couple of things, put in substrate and food, and popped Wheatley in to settle. Today I pulled out the middle shelf, added a thin rope for him to climb around, added the plastic house the cage came with (that I originally set aside - and as soon as I get a wooden or woven grass, etc, house, it'll be replaced), added a swing and hanging rope... It's not amazing, but it's a definite improvement.
We hung out for a while. I picked him up a couple of times, and after I put him back in the cage he cautiously stepped onto my hand, scurried up my arm, and then back down into the cage. He's such a little sweetheart and hasn't nipped at all yet, unlike SOME mice I could mention!
Jen from the Black Dog Blog suggested, on yesterday's post, getting a friend for Wheatley. Unfortunately for him, it is highly suggested to never house male mice together unless you're an experienced mouse-keeper. They can be absolutely fine for months... and then you come home or wake up to dead or horribly injured mice, with no warning bullying beforehand. I couldn't house him with a female either, unless I wanted a million baby mice. I've heard some good things about housing male mice with female multimammate mice, but that comes with risks, too.
For now, I'm going to see if Wheatley will be able to be alone if he has enough interaction with me, which he should be fine with. He's much more social than the girls were when I first got them, so I think he'll be okay.