Many store-bought toys are made of plastic, and while there is no harm in this, it is unlikely to give the satisfaction when chewed as wood. If you have an apple tree in your garden try giving him a branch – he will love chewing this. Other than this, and wood which is dry, clean and not in any way rotting should be fine.

Try to strip the bark off any wood you use from the garden and dry it for several days after washing over a heater. You can create a lovely smooth, clean branch by stripping off the bark. Hamster and gerbils also love everything made of cardboard, including egg cartons, cardboard tubes and more. He is likely to chew these until they are little more than a pile of shredding, but he will get valuable exercise from this activity and will use much of it for bedding material.