Lacking oxygen in dung-beetles in the open (3,2,5)
I believe the answer is:
out of doors
'in the open' is the definition.
(I've seen this in another clue)
'lacking oxygen in dung-beetles' is the wordplay.
I cannot really see how this works, but
'lacking' could be 'outof' (to be out of something is to lack it) and 'outof' is found in the answer.
'oxygen' could be 'o' (O is the chemical symbol for oxygen) and 'o' is located in the answer.
'beetles' could be 'dors' (I've seen this in another clue) and 'dors' is present in the leftover letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for out of doors that I've seen is " in the open air".)