"Does it make you cringe?"

From time to time, yes ;-)

Thanks for all the helpful and the downright silly responses. I used to be a bass player so maybe it's me making the smell...

As it's an old Victorian terrace (row house, I think, to US 'Catters) and the smell is from near the adjoining wall with my neighbour and it isn't a cavity wall, I don't think anything can be trapped (also he doesn't get the smell in his corner).

Thanks to Mudcat I'm going to:

- Get into the crawl space with a flashlight and a small trowel;
- Look into enzymes - whether it be scary looking cleansing products       or washing powder;
- Hope like mad I don't have to take Gnu's advice and rip the floorboards up!

I don't think any bees were involved - the honey smell is almost certainly non-bee in origin.

Thanks again for all your suggestions!