10 World’s Biggest Unsolved Mysteries. #2 Gave Me Goosebumps

Do you know of any unexplained mysteries? No, not conspiracy theory stuff like the Yeti, actual mysteries, like science being unable to explain how hummingbirds fly.
How hummingbirds fly is a relatively mundane mystery. These, however, are not. Watch on and marvel and try not to think too hard about these mysteries lest they drive you crazy.

https://youtu.be/r9WqBGZWHvI