One of the more surprising highlights of my recent UK trip was chatting with a gentleman on my bus to Camden Town. He said he worked in the coal mines near Newcastle before they got shut down. His job was sorting and collecting. I was very happy he was still around to enjoy his life at his age... and then I asked him about the canaries. Apparently, canaries are the ideal animals to detect carbon monoxide because their hearts beat 500 times a minute. So, if there is even the smallest amount of carbon monoxide, their heart will slow down and they will sit on the bottom of the cage. There was a man whose job it was to carry the bird around the mine to check the air levels. The moment the bird noticed something was wrong, the man would give it a little oxygen mask or something and then lead all the men out. The gentleman told me that the company he worked for took amazing care of those birds, and that, in all the time he worked for them, they lost 7 men, but no canaries. It was an amazing experience chatting with him, and it was great he never got black lung.