![Photo from acaquarium.com](https://i0.wp.com/breathtakebyways.com/wp-content/uploads/2016/09/pencil-sea-urchin.jpg?resize=760%2C570&ssl=1)
Photo from acaquarium.com
Believe it or not most visitors to the touch pool at the Denver Aquarium take me up on the offer and get a thrill out of their hug. Why do these sea urchins gently squeeze our finger between their spines when we give them a chance? I’d tell you, but I’m afraid that if I look it up I’ll find out that the “hug” is an unfriendly reflex of some kind, and that would spoil everything.