One of the macaques at a Texas sanctuary, where researchers ran tests to see if the monkeys became germophobes after experiencing a viral outbreak. Stephan Kaufhold hide caption

Stephan Kaufhold

In the very early days of COVID-19, millions who'd rarely thought twice about germ avoidance became germophobes.

Some folks wiped down groceries before stuffing them into the refrigerator. Others let mail quarantine outside for days lest it harbor stray viruses. With the hindsight that SARS-CoV-2 spread primarily through the air, these sorts of precautions seem extreme. But in the moment, they were perhaps reasonable ways of avoiding an unknown pathogen.

Around this same time, a different virus hit a macaque sanctuary in Texas. New research suggests the monkeys responded in similar ways as humans did to COVID-19 — by being extra germophobic.

Humans are far from the only animals to avoid possible sources of disease.…