Dr. Tim Littlewood handles more gross and terrifying creatures than just about anyone in London.
And he loves it.
"I'm a parasitologist," he explains, "so I tend to work on things that live inside other animals. And most people think of them as quite gross and revolting. But upon looking at these things and studying them, [I find] they are the most beautiful, spectacular animals you can find."
Although you wouldn't want to get one inside of you.
Littlewood works in London's Natural History Museum, which is a temple to science. The halls are lined with stone arches in amber and blue. Ceilings are vaulted like a cathedral, with sunlight streaming down onto the specimens below.
Littlewood leads us into the museum's depths, where slithery creatures lurk, unseen by tourists.
Our first stop was a plain set of cabinets — buzzing with history. The cabinets were owned by the Rothschild family — as in Baron Rothschild — and he was an avid collector of fleas.
Now fleas may not strike you as the most interesting of parasites, but Littlewood quickly corrects this misapprehension.
"I think they're great," he says. "They're small, they jump enormous heights, they do horrible things to people. What can be more fascinating than that?"
In Littlewood's tour of tiny terrors, we move on to a roundworm known as anisakus simplex. "They look a lot like vermicelli," he says. "A couple of inches long."
And you could run into one at the neighborhood fishmonger. "Now it wouldn't be too unusual for you to take a piece of marine fish that you bought from the market nice and fresh, and you start fileting it and a couple of these things start wriggling out," says Littlewood.
If you cook the fish, you'll be okay.
On the other hand, if you're a sushi fan, be wary. You could ingest one of these roundworms. "It is extremely unpleasant because they burrow inside your flesh, and they like to dig around," Littlewood says.
Fish aren't the only potentially hazardous food.
"When you talk to a parasitologist, I can put you off pretty much any food stuff there is," he says. "We can put you off meat quite easily. But I can also put you off plants."
A parasite known as a liver fluke will "put their larval stages on plant material," Littlewood says. "A classic case is watercress." If you ate watercress that carried liver fluke eggs, "you would have a lovely population of flattened liver flukes."
But you don't have to worry about the fat parasite that looks like a grub. They're known as isopod crustaceans. They have legs and exoskeletons and look like mini-armadillos.
"Inspiration for Hollywood movies I'd say," Littlewood says. Fortunately, they're found in fish, clinging to the tongue, which will begin "to atrophy, degrade and fall apart, but the isopod stays there, so it becomes a functional tongue."
Littlewood pauses to admire the new role: "That's a beautiful adaptation as a parasite."
He shares one last parasitic worm, brought in by a member of the museum staff.
It came up due to "natural processes," says Littlewood. "[The staff member] was alarmed one morning to see something unexpected in his bathroom, and good soul that he was, remembering that this was a biological specimen and shouldn't necessarily be flushed away. he retrieved the specimen and brought it to us."
This is one parasite story with a happy ending, reports Littlewood: "In the case of this particular individual, this singular problem solved itself."
As a footnote, I emailed Littlewood to inquire whether Halloween candy is safe from parasites. Children everywhere will be happy to hear his response: "There should be no parasites in Halloween candy."
ARI SHAPIRO, HOST:
Saturday is Halloween, and this man...
TIM LITTLEWOOD: Hi. My name's Tim, Tim Littlewood. I work at the Natural History Museum here in London.
SHAPIRO: ...Handles more gross and terrifying creatures than just about anyone in England, and he loves it.
LITTLEWOOD: I do. I'm a parasitologist, so I tend to work on things that live inside other animals. And most people think of them as quite gross and revolting, but upon looking at these things and studying them, they are the most beautiful and spectacular animals you can find.
SHAPIRO: Well, appropriate for Halloween, then, let's take a look at some of the perhaps gross, perhaps revolting, perhaps beautiful creatures you've got in your collection.
LITTLEWOOD: I'll try and convince you.
SHAPIRO: This building itself is as beautiful as any creature. London's Natural History Museum is a temple to science. The halls are lined with stone arches in amber and blue, ceilings vaulted like a cathedral with sunlight streaming down onto the specimens below. Doctor Tim Littlewood leads us behind the scenes into the museum's depths where slithery creatures lurk unseen by tourists. Our first stop is a plain set of cabinets buzzing with history.
LITTLEWOOD: So these are cabinets that were owned by the Rothschild family, as in Baron Rothschild.
SHAPIRO: What decade are we talking about?
LITTLEWOOD: Sort of late-1800s up to the early 1920s. And Rothschild was an avid collector of fleas. And so what you're seeing here are some incredibly small specimens.
SHAPIRO: These are so tiny. Each one is like a speck of dust.
LITTLEWOOD: They are. All of these slide cabinets (unintelligible) must be hundreds of drawers within which there are tens to 50-or-so slides each, so there are thousands and thousands of specimens here.
SHAPIRO: All right. Well, show us what else you have.
LITTLEWOOD: OK, so I started with fleas because I think they're great...
LITTLEWOOD: ...Even though they're...
SHAPIRO: That's a sentence I've never heard spoken before.
LITTLEWOOD: Well, they are great. They're small. They jump enormous heights. They do horrible things to people.
LITTLEWOOD: What can't be more fascinating than that?
SHAPIRO: Fascinating - absolutely - yuck - absolutely. And things are about to get much worse or better if you're a parasitologist. Welcome to the worm room.
LITTLEWOOD: So this is Anisakis simplex. Anisakis is a roundworm, and you can see - what? - a few thousand, perhaps, worms here?
LITTLEWOOD: They're each maybe a couple of inches long, and they look a lot like vermicelli
SHAPIRO: (Laughter). Egg drop soup, maybe.
LITTLEWOOD: Yeah. Egg drop soup - exactly, the sort of thing you might - a condiment for your dish. Now, it wouldn't be too unusual for you to take a piece of marine fish that you bought from the market nice and fresh and you start filleting it and a couple of these things start wriggling out. And they...
SHAPIRO: You're kidding. If I go to a fishmonger, and he cuts open a fish and I see these little things wriggling inside, if I cook the fish, am I going to be OK?
LITTLEWOOD: If you cook the fish, yes.
SHAPIRO: But if I eat sushi, am I going to get these things?
LITTLEWOOD: Yes, you are, and that's going to be extremely unpleasant because they borough inside your flesh, and they like to dig around. The important thing to remember when you talk to a parasitologist - I can put you off pretty much any foodstuff there is.
LITTLEWOOD: So most of the things I...
SHAPIRO: From now on, I will only eat blackened things that have (laughter)...
LITTLEWOOD: So you know, we can put you off meat quite easily, but I can also put you off plants because - I don't think I have one here.
SHAPIRO: So being vegetarian is no safeguard.
LITTLEWOOD: That's no safeguard either because a lot of liver flukes like to put their larval stages on plant material - so classic case is watercress. This is Fasciola hepatica, the liver fluke. This is from the liver of a cow.
SHAPIRO: So this is from a cow that's been grazing on wild salad greens that...
SHAPIRO: ...Had these liver fluke eggs in them. And if I had been eating the wild salad greens, I'd of...
LITTLEWOOD: You too would've had a lovely population of flattened liver fluke like this, yes.
SHAPIRO: In and among these various worms and flukes, you have some fat things that look like grubs.
LITTLEWOOD: Yes. These are isopod crustaceans.
SHAPIRO: They have legs.
LITTLEWOOD: They have legs. They've got exoskeletons.
LITTLEWOOD: They look like mini armadillos...
LITTLEWOOD: ...In some respect.
SHAPIRO: Each one about an inch long.
LITTLEWOOD: And you'll see that the appendages underneath curl around. And they've got these little claw-like appendages.
SHAPIRO: Wait. Wait. Are these inside of someone, or do they go on the outside?
LITTLEWOOD: A bit of both in that grip.
LITTLEWOOD: They're not - no, these are not human - sorry - just before you freak out too much.
LITTLEWOOD: These are found in fish, and they cling onto the tongue. And the tongue begins to atrophy. It begins to degrade and fall apart. But the isopod stays there. So it becomes a functional tongue.
SHAPIRO: You know, now that you say it, the thing looks a little bit like a tongue.
LITTLEWOOD: Exactly. So that's a beautiful adaptation as a parasite.
SHAPIRO: That is a beautiful, beautiful adaptation.
LITTLEWOOD: There you go.
SHAPIRO: Beautiful is definitely the word that comes to mind.
SHAPIRO: You've shown us creatures that have come from South America, Africa, India. Where did you obtain this little sample in this jar right here?
LITTLEWOOD: This was brought up to the parasitic worm section by a member of the Natural History Museum staff.
SHAPIRO: Describe to me how somebody who works at the Natural History Museum delivers this sample to you.
LITTLEWOOD: Well, yes. So obviously, it wasn't through dissection but through, let's say, natural processes. He was alarmed one morning to see something unexpected in his bathroom. And good soul that he was, remembering that this is a biological specimen and shouldn't necessarily be flushed away, he retrieved the specimen and brought it to us.
SHAPIRO: This is a true Halloween horror story.
LITTLEWOOD: Absolutely. So what's important about any specimen in the museum is knowing, where does it come from; when was it collected?
SHAPIRO: And the date is 2012, so these problems are still with us.
LITTLEWOOD: They certainly are. I think in the case of this particular individual, this singular problem solved itself.
SHAPIRO: (Laughter). Thank you very much for this tour. It's been a - well, I'm not sure if I would say a pleasure, but it's been fascinating.
LITTLEWOOD: Great. You're very welcome. Do come again.
SHAPIRO: And happy Halloween.
LITTLEWOOD: And happy Halloween.
(SOUNDBITE OF SONG, "PARASITE")
KISS: (Singing) Parasite lady, parasite eyes...
SHAPIRO: Dr. Tim Littlewood of London's Natural History Museum. By the way, today, he emailed us with some good news. Quote, "there should be no parasites in Halloween candy." Transcript provided by NPR, Copyright NPR.