Patrolling Australian Wildlife Conservancy’s Dakalanta Wildlife Sanctuary as part of an annual fauna survey, one research volunteer was recently confused to find a small, mysterious animal, no bigger than her thumb. Curious, the volunteer called for backup.

“[She] yelled out that she had a ‘sleepy mouse’ in her trap,” Australian Wildlife Conservancy senior wildlife ecologist Dr. Alexandra Ross told The Dodo.

According to Ross, when researchers uncovered the true identity of this little animal, it “just about made the team combust.”

“When the volunteer brought the ‘sleepy mouse’ over and I got a glimpse of the ears, I knew exactly what she had found,” Ross told The Dodo. “The whole team was ecstatic to see their first western pygmy possum.”

Western pygmy possums are tiny marsupials native to Australia. After a record-breaking drought in the region between 2018 and 2019, populations of native animals at Dakalanta, including the pygmy possums, began to dwindle.

Conducting their most recent survey, researchers hoped to see these possums, but kept their expectations low. That day, researchers found six possums, an “unheard of” number, according to Ross. By the end of the survey, researchers had found 29 western pygmy possums — an incredibly promising sign.

“Every additional possum [made] us more and more excited about what this meant for the species in the region,” Ross said.