Quick to bite? (5)
I believe the answer is:
nippy
'quick' is the definition.
(I've seen this before)
'bite?' is the wordplay.
I cannot quite see how this works, but
'bite?' could be 'nip' (nipping is a kind of biting) and 'nip' is located in the answer.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for nippy that I've seen before include "Fast - cold" , "inclined to bite?" , "Speedy - cold" , "A bit cold?" , "brisk" .)