Australia is one of the world’s most beautiful places.

From the Opera House to the Great Barrier Reef, there’s more than enough to feast your eyes on. The continent is home to multitudes of wildlife and marine life. Plus, it’s known to house some of the most outrageous creatures ever reported.

Flying foxes, pythons eating everything, snakes everywhere — you name it, Australia has it. As if its oceans can’t get any weirder, we just stumbled upon this story of crabs forming a pyramid.

Yep, you read that right: A crab pyramid. Pink Tank Scuba was diving off the coast of Blairgowrie Pier in Port Phillip Bay, Victoria when they saw the majestic site. At first they thought it was an unknowing corral just chilling on the ocean floor. When they got a little closer, they realized there were countless spider crabs piling on top of one another.

The two divers stayed calm as they slowly approached the pyramid. The spider crabs also seemed undisturbed by them. But what’s really going on?

Were they turning themselves into a weapon of mass destruction? Were they getting ready to attack the divers? Were they having a cheering competition? Nope. Not exactly. They’re doing their pre-migration routine, holding chunks of food and shells in their pincers. These spider crabs are pretty easy to find because they’re present in shallow waters during migration.

The entire migration occurs annually, from April to July and would usually last two to five weeks when the water temperature will drop to 14 degrees Celsius.

When asked if it was scary being that close, Pink Tank Scuba replied: “Not at all – they are gentle little souls and would never even think of hurting a person.”