Misbehave in front of petfood store (4,2)
I believe the answer is:
play up
'misbehave' is the definition.
(I've seen this before)
'front of petfood store' is the wordplay.
'front of' says to take the initial letters (the letter at the front of the word).
'store' becomes 'layup' (I've seen this before).
The first letter of 'petfood' is 'p'.
'p'+'layup'='PLAY UP'
'in' acts as a link.
(Other definitions for play up that I've seen before include "Cause problems" , "(Equipment) misbehave" , "make too much of a story" , "Behave uncooperatively" , "(Equipment) start malfunctioning" .)