The University of Michigan Library was shut down not because of the pandemic, but because of spiders. It was closed a couple days because three types of Mediterranean recluse venomous spiders being spotted.
The spiders were on the Ann Arbor campus and taken to U of M Dearborn where Professor Ann Danielson-Francois identified them, "They don't have a huge amount of venom, but they have enough to start necrosis, which is the eating away of the flesh." UPI