This might sound like a silly question but does he have plenty of other things to chew on? Those antos chews are very popular. Also the cardboard chew tubes - quite tough cardboard. Our hamster is the opposite - quite solitary and doesn't come out much except when we're asleep or when I get him out for out of cage time. I get him out once a day now at about 8pm (after our dinner and before his evening nap!) for out of cage time and he's getting used to that now - it's better now I have a few out of cage toys. Would that be possible? Sorry if you're doing that anyway. Also I've read that hamsters love labyrinth houses so much that they rarely come out of them, so would it be an option to get one of those? I think they love them because it is like being underground with tunnels and they can have separate areas for nesting and hoards. This one seems popular, although maybe not for a big syrian - there are bigger ones available but they are more expensive - there seem to be plenty of syrian owners using them by the reviews. I just got a big wood guinea pig house and we've hardly seen ours since! So have the opposite problem! Actually, the one I was thinking of might not be good if he is a chewer as it has nails in - the more expensive one doesn't have nails in and is from Germany but postage is quite reasonable (you need google Translate to read it!)
There are 3 sizes on here ranging between about £15 and £22 plus postage. If it's a big syrian you'll need the bigger house. The second one is no good for a syrian but the first one would be ok for a medium or small syrian.
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