A remarkable video shows the moment a gray whale sought help from a whale-watching captain in Mexico to have parasites picked off its head.

The footage, posted to Facebook in March, was taken by a passenger on a whale-watching boat operating in the Ojo de Liebre, a lagoon on the Pacific coast of Mexico's Baja Peninsula.

It shows a gray whale approaching the small tourist boat as the captain, identified as Paco Jimenez Franco, starts picking whale lice off its head.

The whale remains for a while, spinning around long enough for Franco to give her a thorough cleaning as onlookers laugh.

You can watch the footage here:

Franco, who has been working as a whale-watching captain for 20 years, told The Dodo that it took the whales some time to get comfortable around him before he was able to start picking lice off them.

Speaking about his first one-on-one encounter with the whale, Franco said: "Once I removed the first one, she approached again so that I could continue to do so."

"I have done it repeatedly, with the same whale and others. It is very exciting for me," Franco added.

Whale lice are external parasites that are commonly found in skin lesions, nostrils, and eyes of whales. They can be beneficial for the whales because they eat algae on their bodies and feed on flaking skin.

Mark Carwardine, a British zoologist with experience in the region, told The Guardian that gray whales have a "love-hate relationship with their whale lice."

"They have very sensitive skin, and thousands of these little creatures holding on tight, or moving about, with their exceedingly sharp, recurved claws, must drive them nuts," Carwardine said. "It can actually hurt when a whale louse grabs hold of your finger – it feels like tiny pinpricks."

Gray whales, which can grow up to 50 feet in length, earned the nickname "devil fish" because of their ability to fight back when harpooned by whale hunters in the 20th century.

They are frequently seen in Baja California as their migration route spans along the North American coastline.

Franco's interview comes amid reports of orcas ramming boats off Spanish and Portuguese coasts.

In one incident in the Strait of Gibraltar last month, a pod of orcas threw a yacht around "like a rag doll" and ripped off both rudders, Insider's Joshua Zitser previously reported.

This article was originally published by Business Insider.

More from Business Insider: