Why is my rat chewing on the plastic cage and how do I stop it

A rat gnaws on plastic mainly out of boredom and stress. If it doesn't have enough activity and mental stimulation, it looks for a way to "entertain" itself - and the plastic cage walls become the target. It's also possible that the cage is too cramped, the air is stale, or the rat is just fed up with the monotonous environment. There's a third reason too: if a rodent hears something or smells food behind the plastic, it gnaws more actively, trying to reach the source.

To stop this, first of all give your rat more entertainment. Put cardboard tunnels in the cage (they're easy to replace when they wear out), wooden toys, and mazes. Let it gnaw on safe materials like bark, branches, or sticks - when it has a proper "edible" outlet, plastic becomes less appealing. Clean the cage more often so odors don't build up.

If possible, make the cage bigger or at least let your rat run around under supervision - physical activity relieves stress better than anything else. Reconsider whether the cage is near annoying factors (refrigerator, noise). And check if your rodent has dental problems - if its teeth have overgrown, it's gnawing not out of boredom but because of discomfort.