292 | Jonathan Birch on Animal Sentience

1584.178 - 1607.877 Jonathan Birch

And the hermit crabs, they're interesting because they have very strong preferences for certain types of shell. And in the wild, you see them exchanging one type of shell for another. And they have this hierarchy of what they think the best shells are. And Elwood, in these experiments, he drilled holes in the shells, put little electrodes in and administered small electric shocks to the crab.