A rodent is a small animal belonging to the mouse or rat family and is usually considered a pest.
In 2371, Doctor Ma'Bor Jetrel visited the Neelix aboard the USS Voyager in order to screen him for a fatal blood disease, caused by a weapon of mass destruction, created by Jetrel himself. Neelix refused saying that Jetrel "would have to find another laboratory rodent to help him in his experiments".