Kids who bite? (7)
I believe the answer is:
nippers
'kids' is the definition.
('nipper' can be a synonym of 'kid')
'bite?' is the wordplay.
I cannot really see how this works, but
'bite?' could be 'nip' (nip is a kind of bite) and 'nip' is found in the answer.
This explanation may well be incorrect...
'who' is the link.
Can you help me to learn more?
(Other definitions for nippers that I've seen before include "Small children" , "Claws; children" , "They put the squeeze on" , "pickpockets" , "Youngsters" .)