Small rodent’s sleeping-place beside Yorkshire river (8)
I believe the answer is:
dormouse
'small rodent's' is the definition.
(I've seen this before)
'sleeping-place beside yorkshire river' is the wordplay.
'sleeping place' becomes 'dorm' (dormitory).
'beside' means one lot of letters go next to another (I've seen this in other clues).
'yorkshire river' becomes 'ouse' (the Ouse is a river in Yorkshire).
'dorm'+'ouse'='DORMOUSE'
(Other definitions for dormouse that I've seen before include "Creature in teapot (Alice)" , "Alice tea party creature" , "Small British rodent" , "one falling asleep over tea" , "Small rodent that hibernates in winter" .)