For the past 20 years, Paco Jimenez Franco has been a whale watching captain in the waters of Ojo de Liebre, a lagoon on the Pacific coast of Mexico’s Baja Peninsula. There, he’s had a front row seat to these extraordinary animals — sightings of whom Franco regards a gift.

And he’s found a special way of giving back.

On occasions when whales would arrive close to Franco’s boat, the captain noticed some were carrying whale lice — common parasites that attach themselves to various parts of a whale’s body.

It’s unclear if the lice necessarily cause whales discomfort, but some theorize that their breaching behavior may be an attempt to dislodge them as unwanted hangers-on.

Suspecting that to be the case, one day when a whale got close enough, Franco picked some lice off of her. And sure enough:

“Once I removed the first one, she approached again so that I could continue to do so,” Franco told The Dodo.

Since then, that same whale has made a habit of visiting Franco on his boat for additional lice removal sessions. Arriving close, she’ll lift her head from the water within Franco’s reach — remaining there long enough for him to give her a thorough cleaning.

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

Here’s footage of Franco’s kindhearted routine:

Although touching whales is generally prohibited in many places around the world, within designated regions along the coast of Baja California, it is said to be permitted in cases like this one — wherein it is the whale herself initiating that interaction.

From Franco’s experience, having been chosen as a trusted “cleaner” to the whales, these up-close encounters have only deepened his appreciation for them.

“I have learned, by seeing their behavior, that there is a certain nobility in them,” he said. “They’re incredible.”