Grubs (6)

I believe the answer is:
larvae
'grubs' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for larvae that I've seen before include "Immature forms of invertebrates" , "Immature forms of insects" , "Grubs" , "Eg, caterpillars" , "Insects in the first stage of life" .)