Larks in bushes (6)
I believe the answer is:
capers
I believe this is a double definition.
'larks' is the first definition.
(lark can mean a caper or bit of fun)
'bushes' is the second definition.
(caper is a kind of bush)
'in' is the link.
(Other definitions for capers that I've seen before include "Pickled flower buds used in sauces" , "Escapades or pungent flower buds" , "Skips, dances" , "Antics and pickled buds" , "Light-hearted fun" .)