Shout right at insect (4)
I believe the answer is:
rant
'shout' is the definition.
(I've seen this in other clues)
'right at insect' is the wordplay.
'right' becomes 'r' (common abbreviation).
'at' is a charade indicator (letters next to each other).
'insect' becomes 'ant' (ant is a kind of insect).
'r'+'ant'='RANT'
(Other definitions for rant that I've seen before include "Speak wildly and incoherently" , "Show anger" , "Speak intemperately" , "Angry tirade" , "bombast" .)