Aardvark's diet (4)
I believe the answer is:
ants
'aardvark's diet' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ants that I've seen before include "workers found returning" , "Hard workers" , "Inhabitants of a formicary" , "Emmets" , "24 [INSECT] s" .)