Rodent catcher (9)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
mousetrap
'rodent catcher' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for mousetrap that I've seen before include "Snare for vermin" , "For instance, old Cheshire" , "inferior cheese" , "pest control device" , "Boring hard cheese (informal)" .)