Not hard to talk with small animals (4)
I believe the answer is:
cats
'animals' is the definition.
(cats are animals)
'not hard to talk with small' is the wordplay.
'not' indicates named letters should be taken away.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'to talk' becomes 'chat' (chat can mean to talk).
'with' is a charade indicator (letters next to each other).
'small' becomes 's' (abbreviation - e.g. clothes size).
'chat' with 'h' removed is 'cat'.
'cat'+'s'='CATS'
(Other definitions for cats that I've seen before include "Musical; jazz fans" , "Carnivores - stage musical" , "Popular musical" , "Some 6 Downs" , "1981 Lloyd Webber musical" .)