Why does the third floor smell awful? Like gym-socks-and-dead-opossum awful?
I suspect it is because an opossum did, indeed, die on the third floor of Morrill Hall. Who knows what is dwelling in the walls.
The more likely answer, however, is that the people who dwell in Morrill Hall smell that way. Think of it: this building is mostly inhabited by professors and grad students who spend long hours forgetting that they have bodies.
It has been said that, if you walk into the conference room on the second floor after a faculty meeting, you will be overwhelmed with a smell of stale coffee breath so strong that you may not be able to breathe. It’s an odor that can’t quite be adequately described in mere words; one must experience it for herself.