One argues with one animal about another (7)
I believe the answer is:
debater
'one argues' is the definition.
I can't tell whether this defines the answer.
'one animal about another' is the wordplay.
'one animal' becomes 'deer' (deer is a type of animal).
'about' is an insertion indicator.
'another' becomes 'bat' (I can't explain this - if you can you should believe this answer much more).
'deer' enclosing 'bat' is 'DEBATER'.
'with' is the link.
Can you help me to learn more?
(Other definitions for debater that I've seen before include "Wrangler" , "One engaged in public argument" , "One arguing" , "speaker at Oxford Union" , "disputatious type" .)