Wild animals a nuisance for the most part (4)
I believe the answer is:
apes
'wild animals' is the definition.
(apes are wild animals)
'a nuisance for the most part' is the wordplay.
'nuisance' becomes 'pest' (I've seen this in other clues).
'for the most part' means to remove the last letter.
'pest' with its final letter taken away is 'pes'.
'a'+'pes'='APES'
(Other definitions for apes that I've seen before include "Mimics like primates" , "Copies the primates?" , "Large primates" , "Zoo animals" , "Peas (anag)" .)