I have all the things in my hives: screaned botttoms, upper notchs in inner covers, all my hives are tilted, and I do not have "moisture problem". So far (knock on he wood) I have 100% survival through the winters. But even though when I open the hives in the spring in some the outer frames are kind of wet and greysh. And this is what I was just thinking about "aloud" to prevent this excess. I agree, may be it's overkill. A propos "American bees try to escape" the reason is known and it's defferent.