Murmuration.

If you've not seen this video, you need. Two girls take a trip down the River Shannon in Ireland and come across one of nature's most rare and phenomenal occurrences. Watching videos on nature is so often humbling and awe-inspiring, see anything by the legendary David Attenborough (Planet Earth, Life, Frozen Planet), though this video is not on the same sort of scale as Attenborough, it has a great rawness and feeling of the immediate power the birds possess to it.