A mammal who has teeth that grows sometimes,so they chew on some objects to keep their teeth short.Mice,Hamsters,Guinea Pigs,and Squirrels are some kinds of rodents.
A noisy or otherwise annoying child. The term is similar to 'rug rat' or 'yard ape' but is intended to be purely derogatory and not in the least affectionate.
Background? I've been using the term for years, but not sure if I invented it or picked it up from somewhere else...