Today, PETA called for an investigation by the U.S. Department of Agriculture (USDA) after obtaining documents showing that a marmoset monkey confined at the University of Massachusetts–Amherst (UMass) escaped and injured another caged, stressed monkey. The monkey was imprisoned in the laboratory of experimenter Agnès Lacreuse, who studies menopause using marmosets—even though the species doesn’t experience it.

This is the fourth known escape of a monkey in recent years, in addition to multiple other violations.

“UMass is clearly incapable of keeping marmosets safe—even in the confines of a laboratory,” says PETA Vice President of Laboratory Investigations Cases Dr. Alka Chandna. “PETA urges the USDA to investigate this latest incident along with its lengthy pattern of apparent negligence and take swift action.”

A marmoset is confined at a UMass laboratory in this image obtained by PETA through a Massachusetts Public Records Law request.

The incident adds to a long list of previous animal welfare violations in Lacreuse’s laboratory. In a previous incident, a monkey escaped from a restraint device and his tail was injured so badly by a handler trying to recapture him that it required amputation. In two other incidents in 2017 and 2018, monkeys escaped from transfer boxes and injured other monkeys. A monkey also died after being severely burned when workers left hand warmers on him while he recovered from surgery.

PETA—whose motto reads, in part, that “animals are not ours to experiment on”—opposes speciesism, a human-supremacist worldview. For more information on PETA’s investigative newsgathering and reporting, please visit PETA.org, listen to The PETA Podcast, or follow the group on X (formerly Twitter), Facebook, or Instagram.