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View count:1,973,254
Likes:10,999
Dislikes:1,338
Comments:1,535
Duration:06:27
Uploaded:2015-06-03
Last sync:2017-07-28 14:10
Bullet ants (Paraponera clavata) have the most intense sting of any insect -- but what makes it so painful? Dr. Corrie Moreau walks us through how she extracts their venom to learn more about the chemistry of this remarkable species!

Last week, she showed us how she dissects ants to learn about their gut microbiomes! https://youtu.be/D0HGz4RPLwc

Check out the work happening in her lab by checking out their website: http://www.moreaulab.org/research/
Want to learn more about her work?! Go watch our 2014 Valentine's Day video, "Romantic Ants" https://youtu.be/hWWw3SHCIAw

This research is supported by the National Science Foundation. Thanks, NSF!

Dr. Moreau is also the co-chair and founder of The Field Museum's Women in Science group. (I'm on the committee!) Stay up-to-date with our advocacy here: http://www.fieldmuseum.org/about/employee-groups/women-science

Ant photos courtesy of the incredibly talented Alex Wild! http://www.alexanderwild.com/ Please do yourself a favor and check out his website!

Come hang out in our Subreddit: http://www.reddit.com/r/thebrainscoop/
Twitters: @ehmee
Facebook: http://www.facebook.com/thebrainscoop
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Producer, Writer, Creator, Host:
Emily Graslie

Producer, Editor, Camera:
Tom McNamara

Theme music:
Michael Aranda

Created By:
Hank Green
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Filmed on Location and Supported by:
The Field Museum in Chicago, IL
(http://www.fieldmuseum.org)

Big thanks to Martina Šafusová for providing English closed captions on this video!
(The Brain Scoop Intro plays)

Dr. Corrie Moreau: So the other group of ants that we have today are bullet ants. 

Emily: Why are they called bullet ants?

Corrie: Well, they're called bullet ants because their sting is so painful it feels like you were shot by a gun.

Emily: And you've experienced this firsthand?

Corrie: I have, just once, I'd like to keep it that way.  And so you can see they're actually quite tremendous ants, I mean, they're really foreboding, they're crazy big and they're cool

Emily: Are they the largest ant?

Corrie: They're one of the largest ants. There's another genus called Dinoponera. In some ways larger. Not as painful of a sting, though. This is Paraponera (shows a photo of a bullet ant). We're studying the gut bacteria actually in this group of ants. But we're also interested in the venom. And so what I was telling you is part of the reason we brought them back alive is that at one point I had tried to milk them, because my colleague was like, "It's because we weren't sure if we'd have permits to bring back alive."

Emily: Yeah.

Corrie: You can just milk them. So I can show you how I attempted to do that and I will tell you that it didn't work in the end. When I got the venom back it was actually not usable. But I can grab my equipment (rolls off-camera on her desk chair)

Emily: It's not every day you get to milk a venomous ant. At work.

(Corrie laughs)

(jump cut)

Corrie: So this is our fancy equipment. So if you think about, like, how they milk the venom from spiders, right? Usually they just have them bite something and squirt the venom inside and it's the same principle. So again, we just have their empty tubes, and we have a little bit of paraffin, basically, which is just a waxy kind of paper-y thing that we can stretch across the top of this. And we're going to get them to try to sting through this tube and deposit their venom on the side of the tube.

Emily: Wow.

Corrie: Yeah.

(jump cut)

Corrie: One thing I have noticed is - what's really interesting actually, is with these bullet ants, when you collect them in the wild they're incredibly aggressive. You disturb them at all, and they just go into immediate attack mode. In fact in the field, if you even like blow on them, you can physically hear them stridulate, which is a way of communicating between individuals. And now that they've been in the lab for just a few days, they're actually almost docile.

(jump cut)

Corrie: And so I'm curious to see whether they'll even sting through this. But we'll try.

(jump cut)

(Corrie blows on the tube and shakes it a bit)

Yeah see, she won't even stridulate. So now let's see if we put her abdomen up, yeah, she is depositing her sting through. 

Emily: Oh!

Corrie: See that? 

Emily: Sting it!  Sting it!

Corrie: So you see, she's got her sting out, this is where I don't want to lose control of her.  She'll try to sting through, oh, there, you saw that sting go?

Emily: Yeah.

Corrie: That's huge. 

Emily: Wow.  Focus your anger. 

Corrie: We will try to get another one to sting 

Emily: Come on, ladies.

Corrie: You look like a new victim, raaah, let's get her all mad.

Emily: Yeaaaah!  Oh, she's stridulating!

Corrie: She's actually kinda not mad as much anymore.

Emily: They're--they're just like, they're like, Corrie, we wanna hang out, I thought we were cool.

Corrie: I know, that's probably exactly what they think.

Emily: Like, come on, Corrie, I read your latest paper about climactic regional distribution of my sister species.  I don't even know if that's what you've written about, I don't even know if that--those words even make sense.

Corrie: You don't read all my scientific publications?

Emily: Um, I probably couldn't get through the abstract.  Not--not just yours, but most.

Corrie: I won't take it personally.  Oh, yeah, she's got a very big sting, so let's see if I can get her to--

Emily: Yeah.  Sting it. 

Corrie: So that's how you milk a bullet ant for their venom.  So essentially, just getting them to sting through this material, they have now deposited their venom all over the top of this and inside of that tube, so I can just shove that in there and then take it back to an analytical lab to look at what are the--what's the chemistry within the venom.  Now, I've already told you that that didn't work so successfully, so in a sense, what we need to do is dissect out the venom glad, and that's where it gets a little more tricky, because in this case, you can see they're big and--

Emily: Cranky.

Corrie: Cranky.  And they don't like to hold still.  Do this under the microscope.  Okay, so now, again, we're gonna just pull off her abdomen, oh God, these are some tough ants.  Even tougher than the bullet ants. 

Emily: Wow.

Corrie: So now we've got--

Emily: You did it.

Corrie: --her body separated from her abdomen.  I wanna just tease apart some of the parts of the abdomen and then we can usually pull the venom gland out through the sting.  So I'm just gonna start pulling apart the body, since I don't want to rupture the venom gland, I wanna try not to stab too much. 

Emily: Yeah, this is meticulous work, dissecting ants. 

Corrie: Yeah.

Emily: What is the smallest ant that you'll work on under a microscope?

Corrie: Oh, I'll work on anyone. 

Emily: Even the ones that are so small that you can't even see them on the labels?

Corrie: Yep, even those.  I've had to dissect out their guts, too. 

Emily: How do you even get forceps that small?

Corrie: Suspense, right? 

Emily: Yeah, the pressure.

Corrie: Yeah, nothing like having to dissect on camera, too.  As if it's not hard enough, right? 

Emily: Yeah, all the viewers are at home, quietly judging you.  They're like, well, when I dissected ants last--

Corrie: I was thinking they were biting their fingernails in suspense. 

Emily: Yeah, that too.

Corrie: So at the one end, hmm, let's see if I can put it in a good orientation--you can actually see the left side, if you look through the microscope, you can actually see the sting hanging all the way out.

Emily: Oh yeah!

Corrie: Like a giant hypodermic needle. 

Emily: Yeah.

Corrie: And then starting at the other end on the right side, we can actually start to see those parts of the digestive system.  So first you have the crop, right?  So it's that social food sharing organ, which then transitions into the mid-gut and then into what's called the ileum and then finally into the rectum, and then alongside that is where the venom gland sits. 

Emily: That's amazing.

Corrie: Yeah, it's really awesome.  One of the things that's cool when you first open them up is that the contents within the gut, you can see fat and you can see the trachea and all those other things, and even within the gut, it's either clear like it almost looks like water, or sometimes you can see things that look like waste, but within the venom sac, it's actually almost like oil.  And so when you burst it, it's literally like oil coming out, not like liquid, like, you know, in the same sense. 

Emily: Cool.

Corrie: Yeah. 

Emily: Nice.

Corrie: So now the question is, are you gonna hold a bullet ant for 10 seconds? 

(Endscreen/Credits)

Emily: It still has brains on it.