According to the article, the crabs have been bred in an environment without predators. Therefore they have to train the crabs how to protect themselves in order to survive in the coral reefs. Picture of using puppets to train crabs
I'm kinda surprised to see them training them one at a time. That's going to take ages. "OK, Roger has been successfully intimidated by the nightmare puppet. Looks like Brenda is next in line, someone bring in Brenda."