The exploding ant is exactly what it sounds like. This insect, which only occurs in Borneo, defends itself by quite literally blowing up.
When an exploding ant feels threatened or senses an intruder near its colony, it latches onto whatever bug is invading its territory. Then the exploding ant’s abdomen pops, covering the other insect in toxic yellow goo. To be clear, this is no Michael Bay explosion – there are no flying legs and feelers. It’s more of a “blup” says Magdalena Sorger, postdoctoral researcher at the North Carolina Museum of Natural Sciences in Raleigh. The kamikaze ant, its payload expended, slowly dies.
“The queen is the entity of the colony, so the way to look at an ant colony is like a superorganism,” Sorger explains. “The individual worker is not what matters.” Losing a single worker, particularly to protect the colony, is a lot like losing a cell: if the queen’s OK, the colony is OK.
Ants are the theme bug for Natural Sciences’ annual BugFest on Saturday. The exploding ant – nature’s suicide bomber – is only one of many fascinating ant species showcased. For Sorger’s BugFest talk, “The Coolest Ants,” she admits it was tough narrowing it down to just a few. The fungus farming ants are pretty neat, she notes, as are zombie ants. She and Adrian Smith, head of the museum’s evolutionary biology research lab, both speak in awe about the trap-jaw ant, which is capable of the fastest recorded movement of any living thing.
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Some ants can be pests, says Smith, but the odorous house ants that invade North Carolinians’ kitchens and the fire ants that invade North Carolinians’ socks are only two species out of something like 20,000 known types of ants. And, in some ways, these tiny insects are a lot like us.
“Ants are really interesting to study,” Smith says. “They have all solved the problem of how to live in a society, cooperate, solve problems and compete against other societies.”
Some ants cheat
A lot of the things humans have to deal with as social animals, ants do too. For one, they have practical concerns: they have to construct places to live, with specific-sized chambers for specific functions, and they have to know how many workers should be working in a specific space. Since an entire colony is born from the same queen and thereby closely related, they have to control disease transmission. They also have to deal with something one would assume is limited to humans, or at least animals like us: some ants cheat. From the outside, these colonies appear to be happy societies with passive, obedient workers obeying their queen’s will. Up close, they’re less tidy by far.
“They have to deal with societal cheaters, individuals that use resources to their own benefit instead of the collective benefit,” says Smith. In most ant species, he explains, the workers retain the ability to reproduce – they simply respect the social order and don’t. Occasionally, though, a worker decides to lay her own eggs. When this happens, other workers deal with her one of two ways: they can go through the eggs, seeking and destroying any that smell like they weren’t laid by the queen, or they can physically attack the rebellious worker, stressing her out until her ovaries no longer work.
The lone hunter
If individual ants have their own personalities and quirks, individual species vary wildly, too. The trap-jaw ant, in particular, is little like the black or red ants North Carolinians are accustomed to encountering. For one thing, it’s a hunter – and it hunts alone.
“They look like hammerhead sharks when they walk around,” says Sorger, who has studied trap-jaw ants extensively (and made a few discoveries about them, to boot). They wander the undergrowth with their jaws cocked open as wide as 180 or 270 degrees seeking prey – a springtail, say, or a termite. When such a bug triggers one of the hairs extending from the trap-jaw ant’s head, its mandibles snap shut at upwards of 150 mph.
“That actual snap is the fastest movement ever documented in all of the animals,” says Smith. It’s four times as fast as the mantis shrimp, Sorger offers, or twice as fast as a cheetah can run. The snap is loud enough to hear and, if the ant points its jaws at a solid surface, is powerful enough to propel the ant backward through the air. Sorger has had ants launch themselves out of collection vials this way, only to land on her face and bite her.
“It hurt, but I was so impressed,” she says.
In her work, she’s accustomed to looking closely at very tiny insects – one of her research areas, for instance, involves establishing that two kinds of trap-jaw ant in Borneo truly are separate species. Those two species in particular, she notes with wonder, can also jump using their legs.
It’s not just exotic ants that she finds fascinating, either: fire ant colonies, Sorger says, can survive floods by forming rafts and floating downstream with minimal loss of life. As Smith and Sorger describe, ants are fascinating when you simply look into their social dynamics, the variety among species or their individual quirks. That’s one reason Sorger can often be found engaging them through her camera lens. This is part science, sure, but part art: she’s drawn to this tiny world, and she wants to share what she’s found. This weekend at BugFest, the insect she loves gets its spotlight.
“You see these things that nobody else sees,” Sorger says. “You have to look so close.”
What: Bugfest 2016. Adrian Smith and Magdalena Sorger give presentations at 1 p.m. and 3 p.m., respectively.
When: 9 a.m.-7 p.m. Saturday
Where: N.C. Museum of Natural Sciences, 11 W. Jones St., Raleigh