Octopuses are generally solitary creatures, which is why it’s so uncommon to see two of them together. They aren't always antisocial, though. As Atlas Obscura reports, a cluster of more than 1000 of the creatures was recently discovered off the coast of Monterey, California, and it's the largest deep-sea octopus gathering on record.

Most of the individuals are thought to be females because they were observed in a brooding position. With their limbs inverted and wrapped around themselves, they're forming a full-body shield to protect their eggs. The light purple creatures belong to a species of deep-sea octopus called Muusoctopus robustus, and they were discovered at a depth of about 1.9 miles.

Researchers aboard the Nautilus exploration vessel made the discovery while cruising the Monterey Bay National Marine Sanctuary in search of deep sea sponges and corals. Their ongoing expedition is a joint effort between the National Oceanic and Atmospheric Administration (NOAA) and the Ocean Exploration Trust, and they’ve been documenting their finds on Instagram and via live-streamed videos, including the footage they captured of the octopus “nursery" below.

It wasn’t immediately clear why so many octopuses had gathered in the same spot. Researchers noticed a slight shimmering in the water, leading them to suggest that some kind of fluid might be seeping out of the seabed and attracting the creatures. They don’t know how many octopuses were there in total, either.

“What’s really amazing is we never saw an end to them,” the expedition’s chief scientist, Chad King, tells Atlas Obscura. “And we still don’t know the full extent of how many octopuses are down there. We know there are at least a thousand, there could be a lot more.”

[h/t Atlas Obscura]