Prairie dogs with a taste for peanut butter, scientists reported recently, can now be vaccinated against plague — the Black Death that killed much of Europe centuries ago.

Plague, which arrived in the United States through San Francisco in 1900, has persisted in rodents in the American Southwest. Their fleas may carry the Yersinia pestis bacterium, which causes the illness, and the parasites sometimes bite pets and humans.

Last week, New Mexico reported its third human case of plague this year. (The once-unstoppable disease can be cured with antibiotics if it’s caught early.)

Wildlife officers sometimes try to control plague among prairie dogs by dusting their colonies with insecticides. But that is labor intensive, and pesticide resistance in some fleas has been reported.