The term 'mouse catcher' can be broken down into four crossword solutions: OWL, TRAP, CAT, and barnowl. An OWL is a nocturnal bird of prey that hunts small animals such as mice. A TRAP is a device used to capture animals, often with bait. A CAT is a domesticated animal that is also a natural predator of mice. A barnowl is a species of OWL that is found in agricultural areas and is known for its ability to catch mice. All of these solutions are related to the job of a mouse catcher, which involves using various methods to capture mice.