Said to take advantage of sheep (4)
I believe the answer is:
ewes
'sheep' is the definition.
(I've seen this before)
'said to take advantage of' is the wordplay.
'said' indicates a 'sounds like' (homophone) clue.
'to take advantage of' becomes 'use'.
'use' is a homophone of 'EWES'.
(Other definitions for ewes that I've seen before include "Sheep (females)" , "Adult sheep" , "wool producers" , "Female sheep" , "She-sheep" .)