We have a 15th century, timber framed farmhouse which, because of the construction, has hollow walls and numerous small gaps for creatures to sneak into. This means that we have to keep a constant watch out for mice in the loft. A nuisance but not a real problem.

However, just the past couple of weeks we have heard a 'snoring' in a part of one wall in a bedroom. It is a proper 'snore', not a rustle or flutter or anything scrabbling around but a zzzzz, zzzzz etc. It is during the night and early morning, so I don't think it's a nocturnal creature but I don't really know.

What would be snoring loud enough to be heard ?