Potato smell?

[QueenOfCatan]

For the past few days we've had a strong smell of what we can only really describe as potato in our house that seems to just come suddenly and then disappear soon afterwards. It's a musty smell. Until this evening it's been in our living room and kitchen, but this evening we got it in our bedroom too. Any ideas? We have looked but can't find food anywhere, we did have a small leak in our bathroom before Christmas but that was sorted, could it be left over from that?

I hate to suggest it but maybe mice? Many years ago we had them. The smell was worst at the back of the saucepan cupboard where there was a hole cut out for the gas tap. Perhaps look around for any signs of mice and then take action! Mice do give off a musty smell but I hope that is not the reason for your smell.

I did think that it might be but we had mice when we first moved in year and had all the external holes covered at that point. We have no evidence of mice either. We have pet rats but even when they are free ranging they are limited to the living room where they can't get into anywhere to leave poo or anything and we do a wee check once they've gone home and mop up (though it's rare that they actually wee when out of the cage!)
We have a chimney that's blocked so we're going to check that at the weekend and get somebody in to do a thorough check of it too, just in case something is in there. It's the only other thing apart from a leak somewhere or potentially mice that we can think of.