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Meet the Namaatomorphs, a type of parasite you can find in some streams of Japan.

There are these long roundworms that just squirm around and kind of tie themselves into knots.

And they have this awful habit of bursting out of living insects that doesn't

all endear them to people.

Yeah.

But for a parasiteologist like Chelsea Wood, the strategies Namaatomorphs use to survive

illustrates just how unexpectedly interconnected different species in ecosystems are.

And the vital role played by, you guessed it, parasites.

We're specifically talking here about metazone parasites, so things like flatworms, tapeworms, that kind of thing.

See, Namaatomorphs often jump back and forth between freshwater and an invertebrate host, usually an insect.

In its larva, baby, stage of life, a Namaatomorph can get ingested by a cricket where it starts to grow.

So it has this important problem to solve where it's hanging out in a cricket,

and it needs to find a way to get into an aquatic habitat.

Back into the stream.

So our parasitic Namaatomorph does something I find both disturbing and fascinating.

It induces in its cricket host, what's called a water drive, which is essentially a suicidal impulse on the part of the cricket

to drown itself in nearby freshwater bodies.

Obviously, real bad for the cricket, it dies in the process.

What a little russus.

It digger.

It dies in the process.

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