A small bird that hurts tails of all mice, right? (5)
I believe the answer is:
owlet
'a small bird' is the definition.
(I've seen this before)
'that hurts tails of all mice right?' is the wordplay.
'that hurts' becomes 'ow'.
'tails of' indicates one should take the final letters (I've seen 'tail' mean this).
The final letters of 'all mice right' are 'let'.
'ow'+'let'='OWLET'
(Other definitions for owlet that I've seen before include "Nestling" , "Young nocturnal bird of prey" , "Wise baby bird?" , "Small hooter" , "Offspring of the wise one?" .)