Cave-dwelling fliers (4)
I believe the answer is:
bats
'cave-dwelling fliers' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bats that I've seen before include "Pipistrelles, for example" , "Take a stab at the night creatures" , "cracked" , "Hits" , "Mad; mammals" .)