Hiding in bushes to attack an animal (5)
I believe the answer is:
stoat
'an animal' is the definition.
(type of rodent)
'hiding in bushes to attack' is the wordplay.
'hiding' indicates the answer is hidden within the clue.
'STOAT' is hidden in the letters of 'in bushes to attack'.
(Other definitions for stoat that I've seen before include "Source of ermine" , "furry animal" , "Short-tail weasel" , "European ermine" , "Small carnivore" .)