Edit: Neal posted while I was typing.
Aside from not having a hotspot, what are your temps/setup like?
Mouse hoppers sounds small for adult IMO. How big is he? Have you noticed if he's lost any weight?
Cali kings are notorious garbage cans. A few others will probably agree. Oreo will eat anything I toss in for him whether it's mouse or rat with a stretch of time where he would refuse rats. I'd assume there are a few which would be picky eaters.