To crystallize the character of Mastodon's sixth studio album, Once More 'Round the Sun, I went to the naked mole rat habitat at Pacific Science Center. The parallels were obvious:

• Mastodon's dark, churning rhythms and leads are heavy enough to burrow through earth, the way mole rats do.

• In Mastodon's Grammy-nominated song "High Road," they sing, "You are the plague that was brought here by rats" and "You take the high road down, I take the ground below." Mole rats spend virtually their entire lives in darkness, weaving through subterranean warrens and tunnels.

• The Byzantine architecture of the mole rats' Plexiglas fortress recalls the architecture of Mastodon's arrangements: Corridors connect to corridors, which open to rooms the way Brent Hinds and Bill Kelliher's riffs segue into more riffs and spiraling solos.

Moving on to more physical similarities:

• Much like the tusks of a mastodon, the giant incisors of the naked mole rat are situated outside its mouth (let's call them mini-tusks).

• There's no way around it: Naked mole rats resemble scraggly little human scrotums with legs. They use the sparse hairs on their body as feelers because their eyesight is so poor. Their loose skin evolved to allow them to slide over and under each other in their cramped tunnels. And if the music of Mastodon has anything, it's balls.

Other people at the exhibit that day appeared not to be listening to Mastodon. So I decided to put my theory to the test and invited these strangers to take the Mastodon/Naked Mole Rat Challenge, which consisted of listening to a song on my headphones while watching the half-blind rodents do their half-blind-rodent things and giving me feedback. Only two people accepted. So I called Tom Araya from the band Slayer and got him to do a version over the phone.

Person Number One

(52-year-old male from Bremerton)

Subject listened to "High Road" and seemed uneasy throughout the song's four minutes and 19 seconds. "What's this for?" he asked when it was over. "I thought it was going to be an informative thing about how mole rats evolved from mastodons. Or something about them dying in the Vesuvius eruption. We're here to see the Pompeii exhibit."

I told him the Naked Mole Rat Challenge was an outreach program and asked what he thought of Mastodon. Was the music a good match for the mole rats?

"Not at all," he said. "If you're going to have people listen to music while they look at these things, you should give them something calmer, like Brian Eno or Crosby, Stills & Nash. The music you gave me made me think of fetal pigs. Because that's what these things look like, dissected fetal pigs. I think half of them in there are dead."

Person Number Two

(20-year-old female from the Central District)

Subject listened to "White Walker" and nodded her head for the length of the song. "Beautiful melodies, beautiful guitars," she said. "I liked the tribal drums and the baby crying at the beginning. It's kind of sad sounding. It made me think how epic it would be to dig through the earth with your teeth and live in darkness all the time. The babies are so cute. I want one."

Person Number Three

(Tom Araya from Slayer)

Subject thought for a moment when I asked him if Mastodon made a good soundtrack for naked mole rats. "Mastodon make a good soundtrack for most anything," he said. "Superlative gents, those Mastodon men. 'Round the Sun is a hell of an album. We're all God's creatures, you know? Spinning around this planet of ours. Mole rats are jittery buggers. Can't say I know too much about them. Why are they called naked mole rats?" He then viewed a naked mole rat picture online, and when asked to describe what they look like, he asked, "Can I say nutsack on here?"

Of course you can. recommended