The temperature and hydrometer are recorded on the same device. There's no probes or wiring or anything like that, it's battery powered.
I feed him in his cage, but I have had to keep a good eye on it because I know live feeding can go wrong very easily. After I get the new hide and get all the surface temps, I'll let him settle into the new setup for a few days and then I'll try the rat crawler and I'll completely leave him alone.