People for the Ethical Treatment of Animals supporters on Saturday protested experiments on house sparrows by a Yale University postdoctoral student, holding signs outside Woodbridge Hall while the university’s board of trustees met inside.

The demonstrators decried experiments by Christine Lattin, whose studies on the stress response of sparrows include adding crude oil to bird feed and creating small wounds in the birds.

PETA has known of Lattin’s research since she first started experimenting at Tufts University. The organization in May called for a formal investigation by a district attorney’s office in Massachusetts.

Ashley Byrne is an associate director for campaigns at PETA and one of the primary organizers of Saturday morning’s protest, which included, at least, 13 participants. PETA also held a rally against Lattin’s research in August, the same month they released a report saying Yale had the fourth-worst record of mistreatment of rats and mice used in research.

“She’s tormenting these birds in her lab and doing so for no reason,” Byrne said. “The results don’t benefit human beings. They don’t benefit other birds. They’re not applicable to human beings or other animals.”

Yale’s Vice President for Communications Eileen O’Connor on Saturday met briefly with protestors after stepping out of Woodbridge Hall. She notified them that the trustees’ meeting had no set end time, since demonstrators sought to protest while trustees exited the building. O’Connor said the university stands by its previous statement on the matter, which indicates the university’s laboratories comply with federal regulations and independent accreditation standards.

University spokesman Thomas Conroy did not immediately respond to an emailed request for additional comment on Saturday.

Lattin, who was not immediately available for comment, arrived at Yale in 2014. The university highlighted her research in November 2016, in an article published in an issue of Yale Engineering, focusing on how 3-D printing assisted her research.

According to her website, Lattin’s research focuses on “understanding how different neurotransmitters and hormones help animals successfully choose mates, raise young, escape from predators, and survive harsh winters and other challenging conditions.”

Lattin reportedly studies house sparrows in part because they have been successful “in invading new habitats.”

“One of the major areas of my research is the stress response,” Lattin’s website reads. “While stress helps animals and humans survive and cope with challenges, too much stress is bad and causes health problems.”

Among the demonstrators Saturday was Yale alumnus Hanh Nguyen, who graduated from the university in May and now works for PETA. She joined Saturday’s demonstration because animals “are sentient beings” who deserve “respect and consideration.”

Nguyen said she felt the university kept most students in the dark about animal experiments conducted by college researchers.

“I would love to see Yale do the right thing and stop supporting cruelty to animals,” Nguyen said. “They’re not things, they’re living beings.”