The most common and most likely answer to this crossword clue is the 6 letter word MAGGOT
I've seen this crossword clue in The Daily Telegraph
M
A
G
G
O
T
More clues leading to the result MAGGOT
- Grub shown in periodical taken
- Grub bird picked up after dropping pie
- Fly at an early age
- Time, perhaps, briefly secured for grub
- Larval form wise men mostly understood
- Mother took round good grub
- Golf – after mother fetched grub
- Bot maybe makes all gadgets genuinely operate together from the outset
- Fly when very young?
Buddy explains!

The straight part
We know that "Fly when very young" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fly when very young = maggot.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MAGGOT mean?
MAGGOT noun- A soft, legless larva of a fly or other dipterous insect, that often eats decomposing organic matter.
- A worthless person.
- A whimsy or fancy.
- A fan of the American metal band Slipknot.