A video from the YouTube channel "What's Inside" has reached legitimate viral status with over 40 million views since being uploaded last April 3. The video, called "What's inside a Rattlesnake Rattle?", features the father-and-son duo of Daniel and Lincoln Markham dissecting the rattle on the tail of a rattlesnake.
The channel regularly dissects objects and other animals but the snake video has been their biggest hit. The second highest is a video featuring a dissection of YouTube's Silver Play Button—a trophy that YouTube gives out to channels that have amassed 100,000 subscribers—which has 12 million views.
Their snake video was a big hit as the rattlesnake's signature sound and how it produces it has always been a mystery to most. Surprisingly, they found nothing inside the tail. Like them, we expected the tail to have tiny grains that cause the rattling sound. As it turns out, it's the two hollow layers of hardened keratin inside that causes it.
Watch it here: