[cypher]

A lot of hamsters won’t chew on wood or things sold as chew toys, the whimzee dog chews hat Ria mentioned are about the best thing for them & almost all hams love them.
They may be chewing on the cage because they don’t have enough enrichment or space if the cage is small, they need plenty to explore, lots of hideouts, things like cork logs are good as both a hide & something safe to climb on.
Do you have a sand bath? These are really important for robos to keep their coats & skin in good condition & they really enjoy digging around in the sand too, as big as you can manage depending on your cage size & deep enough to have a good dig in, use chinchilla sand but not dust.
Are you keeping them together? Most pairs will fall out as they mature so you do have to keep a very close eye on them to make sure they’re not fighting or one isn’t stressing the other out, sometimes with pairs you will see that one is smaller than the other as the dominant one may prevent it from getting sufficient food.
If they are together be sure to scatter feed plenty of food so there is more chance of both getting what they need, scatter feeding is also enrichment for them & keeps them busy.
Also if they are together you need two of everything, wheels, bottles, bowls etc & houses with more than one exit.