It might be time to grant the monkeypox virus a new name. Although the virus (mpox for short) was first detected in lab monkeys in 1958, the original host or reservoir has remained unknown.

Identifying the reservoir is crucial, because it gives epidemiologists targets to help control outbreaks. For the monkeypox virus, experts need to shield people from the fire-footed rope squirrel (Funisciurus pyrropus), which lives in the forests of West and Central Africa.

A team of scientists first posted a paper describing their findings on the preprint server Research Square. The researchers pinpointed the mpox source as the bushy-tailed rodent by observing a group of wild sooty mangabeys (Cercocebus atys) in Taï National Park (Côte d’Ivoire). In early 1993, about a third of the observed group there was infected by the virus and four infants died.

The scientists scoured the primates’ hunting area and eventually found an mpox-infected fire rope squirrel carcass less than 2 miles from the mangabey territory. They sequenced mpox genomes from both monkey and squirrel and found them identical.