(Describer) Logos appear: KQED; PBS. A title: Deep Look. Tiny, orange mites climb across the face of a Madagascar hissing cockroach as it nibbles a plant.

[MUSIC PLAYING]

NARRATOR: Is there anything more lowly than the lowly cockroach? Uh, yeah, there is. That's a cockroach mite. It lives its entire life on this cockroach.

(Describer) Words appear: Madagascar hissing cockroach mite.

But these hitchhikers are doing a lot more good than you might think. The mites are only found on one type of cockroach-- these guys, Madagascar hissing cockroaches, which are known for their hiss, of course.

(Describer) A person touches a cockroach's back.

[hissing]

They do that when disturbed or looking for a mate. They only live in the Madagascar rainforest on an island off the coast of Africa.

(Describer) Roaches crawl on dirty dishes.

And they're bigger than the cockroaches you might find in your kitchen, like these brown-banded roaches. These pests will eat anything-- food scraps, poop, trash, you name it. As a result, they can spread disease or trigger allergies. Hissing cockroaches are detritivores. They mainly eat decaying leaves, tidying up the forest floor. They can even be kept as pets because they're more docile than their common cousins. And, more importantly, they are a lot cleaner thanks to a permanent population of tiny house keepers. OK, yeah, it looks pretty bad. The mites crowd together in the crevices, places where the cockroach can't brush them off. They get their meals near the cockroach's head, gobbling up the food bits and saliva that the cockroach leaves behind.

(Describer) A cockroach hangs upside-down from a branch.

When they get thirsty, they head to the spiracles, the openings the roach uses to breathe. The mites get water vapor from them.

(Describer) Just beneath the cockroach's shell.

The roach also has one special hissing spiracle for that signature sound.

[hisses]

The mites live on a single roach unless they get passed on from roach parent to roach baby.

(Describer) A half-sized cockroach on an adult's back.

They're doing these cockroaches a favor. By cleaning up the old food and debris, the mites help keep them free of mold and pathogens-- potentially extending the roaches' lives.

(Describer) Half a dozen mites swarm across a roach's face as it chews on a leaf.

Really, both a hissing cockroach and its mites have the same important job-- keeping the world a little bit neater. Not so lowly after all.

(Describer) Credits appear: Producer/Writer: Jenny Oh. Cinematographer: Josh Cassidy. Narrator/Writer: Lauren Sommer. Original Music: Seth Samuel. Lead Producer: Josh Cassidy. Funding for KQED Science is provided by the National Science Foundation. Copyright 2020 KQED Inc. kqed.org/DeepLook. Accessibility provided by the U.S. Department of Education.