The first worker has strange outburst (7)
I believe the answer is:
tantrum
'outburst' is the definition.
(a tantrum is a display of anger)
'the first worker has strange' is the wordplay.
'the first' becomes 't' (1st letter of 'the').
'worker' becomes 'ant' (worker is a type of ant).
'has' says to put letters next to each other.
'strange' becomes 'rum' (similar in meaning).
't'+'ant'+'rum'='TANTRUM'
(Other definitions for tantrum that I've seen before include "Burst of temper" , "Uncontrolled outburst of anger" , "Display of bad temper" , "Childish fit of anger" , "Burst of rage" .)