Thanks for the help everyone! I've plastikoted his wheel now after a thorough clean so hopefully that will solve the problem of the wheel smelling. Serendipity it's funny you mention the Rosewood pico because that's exactly what he has, hence the problem! However, I put some substrate in his sputnik which is right next to the house and he's started peeing there which is actually pretty convenient as I can just empty it out daily, so it seems like the issue is sorted for now
