The bunny was discovered in the lost-in-found box at the front desk -- just two weeks before Easter -- this past Monday, museum curator of visitor experience Jeff Gray told ABC News today.
"My colleague took a picture of it sitting at the edge of the lost-and-found box and posted it to Twitter with the hashtag #foundbunny," Gray said. "The bunny just took off from there, and we decided to tour it around the museum and share its adventures since it's international #MuseumWeek on Twitter."
The stuffed animal, who the museum is temporarily calling "Found Bunny," took a tour with zoology curator Andrew Hebda on Monday.
"Found Bunny's" escapades and stops at various museum exhibits have been shared on Twitter throughout the whole week.
The floppy-eared bunny has also made a lot of new friends including fellow stuffed animal souvenirs, a turtle named Gus and a taxidermy seal.
"The bunny is very at-home in the museum and is having lots of fun exploring," Gray added.
'Found Bunny' has made itself so "at-home" that it's taken on some big responsibilities like updating the museum's website, analyzing fossils and even using power tools to assist with exhibit renewals.
Twitter users have fallen in love with the plush animal -- and some are asking if they can adopt "Found Bunny," Gray said.
However, the brown bunny is not up for adoption, the museum tweeted.
"We want its owner to know the bunny is doing very well, and we're taking great care of it," Gray said. "But of course, we'd love to see it get home and reunite with its owner."
And if "Found Bunny's" family never comes forward, it will stay with the museum forever, Gray said.