Ever wonder what 100,000 crabs marching along the ocean floor looks like?

Thanks to new footage from Museum Victoria in Melbourne, Australia, you can get an underwater perspective of one of the most unusual migrations on the planet.

Every June spider crabs come in huge numbers to the shallow waters of Port Phillip Bay in Melbourne ahead of their annual winter molt.

Museum Victoria scientist Julian Finn has been filming the exodus using a fisheye camera lens.

The footage will be projected in an immersive dome set up at the museum that allows visitors to stand inside and get a 360-degree underwater view of some of Australia’s most interesting marine life—without getting wet.

Finn and fellow researchers headed to the bay a week before the full moon this past June.

“In this location, it’s a really good time to see spider crabs,” Finn said in a video post on the museum’s website.

What attracts the large gathering of the typically solitary species?

Scientists had thought the gathering was a time for spider crabs to mate as well as molt. But the team didn’t find much sign of that during its filming.

Instead, Finn believes the pilgrimage to the shallows is a way for the crabs to gain safety in numbers. After they have molted, the crabs are extremely vulnerable to predators, so they gather in the way that herds of wildebeests or other mammals do.

Whatever the reason for the march, it makes for a spectacular visual.

The team captured other animals in six locations in Port Phillip Bay, getting 360-degree views of seals, fish schools, and more for Museum Victoria’s Underwater Backyard exhibit.

"Port Phillip Bay is an iconic part of Melbourne, but it's also something most Melbournians know very little about," Finn said in a statement.