The most common and most likely answer to this crossword clue is the 7 letter word SCARABS
I've seen this crossword clue in The Guardian
S
C
A
R
A
B
S
Buddy explains!

The straight part
We know that "Insects" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case insects = scarabs.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 SCARABS mean?
SCARABS noun- A beetle of the species Scarabaeus sacer, sacred to the ancient Egyptians.
- Any species of beetle belonging to the family Scarabaeidae.
- A symbol, seal, amulet, or gem fashioned to resemble the sacred beetle.