Crossword Genius

Bug pervades litter and adds oxygen (9)

Ross

I believe the answer is:

eavesdrop

I'm a little stuck... Click here to teach me more about this clue!

'bug' is the definition.
(I know this)

'pervades litter and adds oxygen' is the wordplay.
I cannot really see how this works, but
'oxygen' could be 'o' (atomic symbol for oxygen) and 'o' is found within the answer.
an anagram of 'pervades' is 'eavesdrp' which is within the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?

(Other definitions for eavesdrop that I've seen before include "Hold secret hearing" , "spy" , "Deprave so to listen secretly" , "Overhear" , "Listen to bug" .)

I've seen this clue in the Sydney Morning Herald.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.