Every spring, a stunning natural spectacle takes place in southern Manitoba, Canada, as tens of thousands of garter snakes emerge from their communal dens to find their mates. This year, Professor Tracy Langkilde, Head of Biology at Pennsylvania State University, captured an incredible photo of the snakes forming a massive knot during their mating ritual.

The dens where the snakes hibernate during the long and harsh Canadian winter are limestone cavern systems that allow them to avoid being frozen. In this particular den, Professor Langkilde estimated there were close to 10,000 garter snakes. In early spring, as the earth begins to thaw, the snakes slowly emerge from the dens in a mass exodus that takes place between late April and the end of May.

Following their emergence, the males stay close to the dens and wait for the females to emerge as the mating season gets underway. When a female snake emerges, several males aggregate around her and form large courting balls. The sight of this can be both fascinating and intimidating.

During the courting ritual, some male snakes even change their pheromones so that other males think they’re female and slither on top of them as well. This behavior not only warms the newly emerged male but also protects him from predators such as crows that loiter around the dens and pick out the liver of cold and largely immobile snakes.

The image of the snakes forming a massive knot during their mating ritual was shared by a local snake catcher, Stewart Lalor from Elite Snake Catching Services, on social media in the past week because it is mating season in Australia, and the snakes’ behavior in Canada is incredibly rare.

In Australia, snakes don’t hibernate in dens like the garter snakes in Canada. Instead, they slow down a bit during the colder months, but they remain active throughout the year. For about three months, Australian snakes go into “brumation,” a hibernation-like state where they become lethargic and sometimes stop moving.

Mr. Lalor said there was no need to fear this many snakes gathering together in Australia. While he had heard of a case of about a dozen brown snakes on one property, he added that it was quite rare.

The mating ritual of garter snakes is a remarkable natural phenomenon that draws attention from biologists and snake enthusiasts alike. As long as humans give the snakes their space, this event can be appreciated and admired for the wonder it is.