The 40 million red crabs avoiding traffic and obstacles on their way to the sea are joined by a robotic spy crab

In this unsettling clip from the BBC/PBS documentary The Islands of Spy in the Wild 2, narrated by David Tennant, a robotic spy crab developed by John Downer Productions joins the 40 million red crabs marching over Christmas Island to the sea. The robotic crab finds itself on the verge of being devoured by a cannibalistic partner, and must scale a fence and avoid massive obstacles and automobiles to get to the other side.

Thousands of Christmas Island crabs march to the sea, including Spy Crab. However, the crabs’ trek to the sea is far from easy, since they must scale fences and avoid oncoming cars as they cross highways.