Have you ever looked up at the sky just before a hurricane and noticed birds swirling and swooping in ways that seem almost ...

The bird would bang into the window, fly back to a nearby tree, calculate its next attack, and then fly into it again. This happened repeatedly over the next hour.

That's the way one scientist puts it — referring to how infected wild birds survive long enough to spread it to birds and mammals around the world. And that's a serious risk for human health.