They often do actually! The pelican cases are quite popular for that purpose. But, like all things, they aren't totally fool-proof. Leaks happen. Even a sma

They often do actually! The pelican cases are quite popular for that purpose. But, like all things, they aren't totally fool-proof. Leaks happen. Even a small air-leak means moisture has an opportunity to condense and penetrate into the container and accumulate. Cracks happen, debris along the gasket, etc. etc. Actually, a more common failure mode than rotting or rats is... simply forgetting where you buried it!