I'm trying work out whether I've got a rat or a stoat living in the stone shed at the bottom of the garden.

Facts so far:

I saw a stoat in daylight running along the rear fence a few weeks ago.

We've rats around (neighbour has hens and he's plagued by them) and I've spotted some on the drive and under the bird table.

Snow paw prints over the last few weeks look like very tiny dog prints.

Apples left out on the lawn for the blackbirds have been carried (in day light) to the gap under the shed door (where they're too large to fit through - door sill has been gnawed a little).

I discovered a bunch of bird feathers outside the shed door last week.

Some scat found on the driveway and rear garden doesn't look like rat crap (but I'm no expert!).

If its a stoat, then I'm stoatally (sorry!) OK with that, as hopefully it will see off some of the rabbits, rats and mice - but I don't want a lodging rat (yeah, I know, I'm prejudiced), and I can't use a trap incase it is a stoat.

Any other ideas about how to determine whose taken up residence, aside from rummaging around in the shed and disturbing it/them (I've not been in for a few weeks but have peered through the window, but not spotted anything)?