Recalled vermin being kept in small enclosure, for example (8)
I believe the answer is:
specimen
'example' is the definition.
(I know that specimen is a type of example)
'recalled vermin being kept in small enclosure' is the wordplay.
'recalled' is a reversal indicator (to recall can mean to bring something back).
'vermin' becomes 'mice'.
'being kept in' is an insertion indicator.
'small' becomes 's' (abbreviation - e.g. clothes size).
'enclosure' becomes 'pen' (pen is a kind of enclosure).
'mice' in reverse letter order is 'ecim'.
's'+'pen'='spen'
'ecim' placed into 'spen' is 'SPECIMEN'.
'for' acts as a link.
(Other definitions for specimen that I've seen before include "Person critically" , "Sample to be studied" , "Example of type" , "Part taken as example of whole or class" , "Test sample" .)