Staple item on the early bird menu? (4)
I believe the answer is:
'item on the early bird menu?' is the definition.
(the early bird catches the worm)
I don't understand how the remainder of the clue works.
(Other definitions for worm that I've seen before include "Cylindrical gear; burrowing invertebrate" , "Reproductive computer virus" , "Screw thread; maggot" , "mean creature" , "Insect larva" .)