[cypher]

It might be worth trying a different house, the igloos aren't the best, plastic can get a bit of a condensation build up & get a bit damp & I don't think they're dark enough.
If you can get a large wooden house that's the best although they do need to be painted inside with a non toxic paint to waterproof them, a cardboard box about the size of a shoe box is great too, if you cut the base out & keep the lid then you can just lift the lid to check inside, cut out a small door & maybe put a bendy bridge in front of the door to make it really dark in there, he would probably still burrow down into the substrate but he might come up for a pee!