Wild deer and rats may be stopped (8)
I believe the answer is:
arrested
'be stopped' is the definition.
(arrest can mean to stop or obstruct)
'wild deer and rats' is the wordplay.
'wild' is an anagram indicator.
'and' means one lot of letters go next to another.
'deer' put after 'rats' is 'ratsdeer'.
'ratsdeer' anagrammed gives 'ARRESTED'.
'may' acts as a link.
(Other definitions for arrested that I've seen before include "Stopped or slowed down progress" , "Apprehended and taken into custody" , "Checked" , "Stopped or slowed down development" , "Taken into police custody" .)