Noisy and very ferocious bats (10)
I believe the answer is:
vociferous
'noisy' is the definition.
(I've seen this before)
'very ferocious bats' is the wordplay.
'very' becomes 'v' (abbreviation).
'bats' indicates an anagram (slang for mad).
'ferocious' with letters rearranged gives 'ociferous'.
'v'+'ociferous'='VOCIFEROUS'
'and' is the link.
(Other definitions for vociferous that I've seen before include "loud" , "Strident" , "Insistently noisy" .)