This is a video from the BBC Documentary Wild Thailand (let's go and never come back) detailing how some Macaque monkeys (nicknamed sea monkeys) there have learned to use rocks to open the shellfish they dive for during low tide. That's pretty smart. For reference, my roommate once tried to open a pickle jar with a knife and stabbed himself in the gut and expected ME to drive him to the hospital. "Did you?" Only after he lost what I deemed an acceptable amount of blood for his poor decision making.
Keep going for the video while I pack my bags and buy an airline ticket to live with these sea monkeys. Shellfish all day, baby -- the dream.
Thanks to Lydia, who agrees this is exactly why they should give you a bucket of rocks at Red Lobster.