I thought this was pretty cool.

It's a bird! It's a cloud! It's a bird cloud
Apologies to Alfred Hitchcock and his creepy movie about evil birds, but sometimes truth can be stranger than fiction. This bizarre swarm of starlings isn't evil, but it's pretty astonishing. A really, really big flock of 300,000 birds created a wavelike cloud over Denmark. According to ornithologists, these feathered friends really do prefer to roost together, and the massive formations are a sort of pre-roost ritual that take on these odd shapes. Sort of like a Rorschach test in the air. Or a flying lava lamp. In short, mesmerizing. As long as they don't attack. Sorry, we just can't get "The Birds" out of our heads. See for yourself.