 and not be able to get out because their claws can't grip on the plastic and they can't get out the top of them. And what happens then is they die because it's very hot in the bottle and it kills them. But when hermit crabs die, they release a pheromone. The pheromone says to other hermit crabs, my shell is available, come and get my shell. And so what happens is as they die, they release this pheromone and more crabs come in and climb into the bottle and slide down and die. And they release their pheromone and more crabs come in