When we still had two cats, they had different ways of indicating hunger or general dischuff. The white-and-black one (some call them "moo cats") would sit and be furious at us; the tabby would just sit and look disappointed.

Nowadays the survivor, the tabby, paws noisily at the glass of the back door if he's actually hungry, or gently lays his paw on the glass if it's just for keeping score.