Hi Christian, we have suffered with fuines in the roof, and only found this out on a visit, when the place absolutely stunk of heaven knows what, really awful, no way could you stay in the loft, even with windows open, I know you have not asked about the smell, but found that looking up 'skunk smell and deterrents' on Yahoo USA was quite helpful. Yes I know for those of you out there, that fuines are not skunks, but they have one thing in common, they leave a very similar calling card, the most awful stink that no amount of washing with or without tomato juice, yes, tomatoe juice, moth balls, air freshners, bleach, the only thing I haven't tried is the peroxide, and this I will do the next time we are down.