What’s a polar bear to do when a rat snake invades its home? Tread lightly, of course.

Anana the polar bear already had to put up with a new roommate earlier this year when the N.C. Zoo moved a male bear into her quarters. But on Friday, in a video drawing both laughs and cold chills on social media, she drew the line at a rat snake that wandered in.

“Can we just point out how non-bothered she is?” a zoo employee said while first filming as the non-venomous snake passed behind the bear.

“Oh, there, she saw it,” the worker then said when Anana turned her head and spied the reptilian trespasser.

The park, outside Asheboro, is the world’s largest natural-habitat zoo, sitting on 2,600 acres in rural Randolph County. All kinds of native creatures pass through it, most without causing any problems for the full-time residents or their caretakers. Once, years ago, beavers invaded and were cutting down trees to build dams on a stream that runs through the property.

As the 22-year-old ursus maritimus rousted from her straw-lined resting place and went to investigate this new interloper, others in the viewing area began speaking for her. “Oh, no! What is that?” one said. “What’s going to happen?”

The snake acted like it belonged there and knew it was on display, oozing brazenly into view.

The zoo does have snakes on display, but not usually in the Rocky Coast exhibit where the polar bears live.

“Anana, leave it be,” the zoo worker instructed, before pointing out the rat snake’s considerable girth.

Anana, who weighs about 600 pounds, pushed her formidable nose toward the errant 3-pound serpent, then jumped back as the snake did the same.

With that, Anana backed up, turned and walked nonchalantly out of the cave, proving she’s smarter than the average bear. Eventually, the zoo said, the snake slithered on as well.