Okay, so this isn’t precisely a library shenanigan, but it’s close enough, I think — people tend to elide museums and libraries.

On May 10, 1922, Colorado College students removed taxidermied animals from the college museum in Palmer Hall and placed them all over campus. This shenanigan was apparently in protest of then-president of the college, Clyde Duniway, whose policies were unpopular with students: he limited the times when men could visit women’s dormitories; strictly enforced chapel attendance; and fired a football coach for using profanity on the field. 350 students (about half the total enrollment) signed a petition complaining about Duniway, to no avail. The animals prank was one of several that spring: students also released hydrogen sulfide in one classroom building and somehow got a live cow up to the second floor of another.

In January of 1929, CC students again placed the museum animals around campus, this time to protest the firing of the editor of the student newspaper.

Source: J. Juan Reid, Colorado College: The First Century (1979), chapter V, “Controversy and Student Unrest.”