Shooting some mosquitoes, by the sound of it (5)
I believe the answer is:
skeet
'shooting' is the definition.
(US shooting sport)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for skeet that I've seen before include "A form of clay-pigeon shooting" , "American clay pigeon shooting" , "Form of clay pigeon shooting" , "US version of a shooting sport involving clay pigeons" .)