The giant squid may be one of the most hard-to-glimpse creatures in the oceans. Since at least the 1500s, rumors have circulated that such a sea creature existed with "a head like a man ... and a dress of scarlet like a monk's cloak," according to the Smithsonian's Ocean Portal.

Five hundred years later, scientists knew this creature was a giant squid, but they were hardly any closer to seeing one live. "Most of what we know comes from dead carcasses that floated to the surface and were found by fishermen," the Smithsonian said.

Finally, in 2006, scientists pulled one up to the surface, after luring it with bait, and caught it on film. But it was not until last year that scientists finally caught the first video of the giant squid in its natural habitat, seen in the footage below.

Marine scientist Edith Widder, who was on the team that found the squid, gave the inside scoop in her 2013 TED talk, detailed below. To get the footage, the team had to completely transform the way it approached deep-ocean investigations.

It would never have happened without a simple but revolutionary idea: "focusing on attracting animals instead of scaring them away," Widder said at a Mission Blue event.

This idea helped her score an invite to the Squid Summit and a proposition from marine explorer Mike deGruy to hunt for the giant squid. To get the squid on camera, they had to be as unobtrusive in the water as possible. Specifically, they had to use quiet vehicles.

In her talk, Widder explained why no one yet had seen the squid:

So my suspicion was that it might have something to do with the amount of noise [the vehicles] make. So I set up a hydrophone on the bottom of the ocean, and I had each of these fly by at the same speed and distance and recorded the sound they made.

At 2:36 into the TED talk below, you can hear the different vehicles:



Instead of using large, loud submersibles, Widder and a team created Medusa, a small, minimalist setup designed for remote squid filming. It has only the necessary features: a camera and a glowing blue lure designed to mimic a jellyfish, which they named e-jelly. It also has red lighting that's invisible to most deep-sea creatures but lights up the scene for us humans.

The Medusa, a minimalist setup designed for squid viewing. Screenshot from TED: How We Found The Giant Squid

The setup has no motor, just 2,000 feet of line connecting it to the surface. It floats around with ocean currents and monitors what's happening deep underwater.

With Medusa, the team was able to entice the giant squid with the glowing lure, not because the squid eat the jellyfish that glow blue but because their blue glow is a defense that signals a predator is near.

And a jelly's predator is a giant squid's prey, according to Widder.

"What really wowed me about that was the way it came in up over the e-jelly and then attacked the enormous thing next to it, which I think it mistook for the predator on the e-jelly," she said.

"Exploration is the engine that drives innovation. Innovation drives economic growth. So let's all go exploring," Widder said.

Check out her story and more video and images in the TED video.