Hard to leave pet rodent with mother in city (9)
I believe the answer is:
amsterdam
'city' is the definition.
(Amsterdam is an example)
'hard to leave pet rodent with mother' is the wordplay.
I cannot quite see how this works, but
'mother' could be 'dam' (female parent of an animal) and 'dam' is located in the answer.
This explanation may well be incorrect...
'in' is the link.
Can you help me to learn more?
(Other definitions for amsterdam that I've seen before include "Capital city" , "City known for canals" , "city with many canals" , "diamond-cutting centre" , "Dutch city of canals" .)