I have just come across the mailbag article What’s the purpose of bags of water hanging in restaurants?
I seem to recall a discussion on the boards about the article, but I can’t find it now. I recently came across the hanging bags of water while visiting relatives, and wondered if there had been any breaking research on this subject since 2001.
My own thought is that there’s no way in hell this could actually work, since a fly has no qualms about landing amidst glasses of water on my table, so how could it possibly be bothered by a bag of water 15 feet away? The article here seems pretty credulous about the idea, and cites no sources at all. It would seem to me that with such an implausible mechanism, and not any information showing it works (at least none cited), this idea has to go into the provisional dust bin.