Sea otters hold hands when they sleep so they don't drift apart, a behavior known as rafting.

Video Credit: Vancouver Aquarium

Full video on Youtube: https://www.youtube.com/watch?v=zHIIzcWqsP0&list=PLc4W06G5-v7BDRHoh7n3QkUKUDJmgMO0n

https://files.mastodon.social/media_attachments/files/110/554/010/192/160/659/original/aea42587b11e3542.mp4