Now that humanity has joined Galactic society, humans are starting to enroll in Galactic universities. At one such, a group of psychology students decide to perpetrate a practical joke on the newcomers. It backfires, however, and ends with the non-humans at the mercy of their victims.

This is the third story set in the "Homo Sol" universe. It’s mildly fun, actually, if a little primitive in style. Still, I'd rank it among Asimov’s better pre-Foundation, non-robot stories.