Cat grabbing a rat's head and part of throat (6)
I believe the answer is:
larynx
'part of throat' is the definition.
'cat grabbing a rat's head' is the wordplay.
'cat' becomes 'lynx' (lynx is a kind of cat).
'grabbing' indicates putting letters inside.
'head' suggests taking the first letters.
The initial letter of 'rats' is 'r'.
'a'+'r'='ar'
'lynx' going around 'ar' is 'LARYNX'.
'and' is the link.
(Other definitions for larynx that I've seen before include "Creator of speech" , "it's essential to speak!" , "Upper part of the windpipe" , "part of neck" , "Human voice box" .)