Training a crab

Lily is 17. She has been clicker training dogs since she was ten, and now teaches public obedience classes. She read my story in Chapter 1 of Reaching the Animal Mind, about training a hermit crab to ring a bell.

So, for her class research project last week at Shoals Marine Lab in New Hampshire, she set out to train a crab to ring a bell. Her professor doubted it would work, but she was so excited about it, he let her try.
Lily collected some of the local hermit crabs around the island. They were very small and timid so she used the local green crab Carcinus maenas instead. (These are pointy-shelled Portunid crabs, like the blue crabs we eat on the East Coast, only of course they are green not blue.)

Lily used the same reinforcement procedure I did--feeding with forceps, using the movement of the forceps as the click. She shaped the behavior of shoving a hanging weight with a claw, an improvement over my more complicated job of pulling a string down.

Just to be safe, in spare moments across two days she trained two crabs, Crab A and Crab B, Abby and Bertha. She took good and thorough data, photographs, and video too. When she presented her project, the other students burst into applause. The professor said her study was ‘practically publishable.'

The crabs really enjoyed the experience. How do I dare say that? For each session the crab had to be moved into a small experiment tank with a grid drawn on the floor (to measure exactly how far the crab came toward the target each time.) At first the crabs were hard to catch, and struggled mightily when lifted into the air. But soon, they got the picture. They held still to be picked up by the shell, and relaxed completely in the air, legs hanging down calmly. Now I ask you: isn’t that cool? Clicker-wise ‘operant’ crabs?
When the experiment was over, Lilly released Abby and Bertha back to the ocean in the same place where they were collected.
I found all this out by accident. I visited the lab with a Cornell alumni group, sat down for lunch at a student table,and was chatting with them when the girl next to me suddenly read my name tag and exclaimed, "You're Karen Pryor! Your book changed my life!" Changed the life of a couple of crabs now, too, I guess.

What were the chances that out of 100 people or more in the room I would sit down next to Lily?


Get more on Karen Pryor at SimonandSchuster.com