Star turn by rodents (4)
I believe the answer is:
rats
'rodents' is the definition.
(I know this)
'star turn' is the wordplay.
'turn' is a reversal indicator.
'star' backwards is 'RATS'.
'by' acts as a link.
(Other definitions for rats that I've seen before include "Snoopy's imprecation - vermin" , "Heels" , "Annoyed expression" , "Oh no" , "Blast" .)