Half a million leafcutter ants will share the title of star attraction when the American Museum of Natural History’s new insectarium opens on May 4.
Ants are biological wonders, living in huge colonies and functioning as a single superorganism. They are skilled farmers, collecting leaves to grow vast fungal gardens that provide food for the colony.
Creating the new Leaf Cutters exhibit was a six-year journey that took the museum’s team — and the ants — from a farm in Trinidad, where colonies the size of oranges were collected, to a laboratory in Oregon, There it grows big enough to fill a bathtub, and it’s six days across the country in a U-Haul van.
And that’s not the hardest part. The ants moved into their museum habitat in January, but they were slow to adapt to their new home and were unable to harvest enough leaves to sustain their fungal garden.
“We’ve had some ups and downs,” said Hazel Davies, curator of live exhibits at the museum. “As we expected, some problem-solving, because this is a very unique exhibition.”
Here’s how the museum ended up helping the ants find their way.
To showcase ants’ farming, the museum has designed a sprawling, open-air exhibit made of lab-tested, “ant-approved” materials, from woven stainless steel to vintage Lego bricks. “Ants have to forage a lot,” says Ryan Garrett, a self-described “ant wrangler” and founder of Leaf House Scientific, who collects colonies and serves as a habitat consultant.
The design sees ants tending their fungal gardens in glass spheres, then following an ambitious route to collect their leaves, hanging upside down across transparent flyovers and climbing over aluminum poles.
The team filled the feeding area with blackberry raspberries and filled the surrounding moat with water to help control the ants.
They then filled the exhibit with ant-filled spheres improvised with Play-Doh balls. (A handheld vacuum was deployed to collect ants that ventured out of the sphere to feed, sucking the insects into a “friendly tornado,” Mr. Garrett said.)
They plucked the spheres and waited for the ants to find their way, a process they expected to take at least a few days.
It took a few weeks. Some ants quickly climbed overpasses and even up the ant highway leading to the foraging area, but they seemed to stop there. “We knew it was a big ask,” Ms Davis said. “It’s like going downtown looking for groceries and not being told where to go.”
The team only needs a small group of ants to make their way; when the first ants return from a foraging area, they leave a pheromone trail for their sisters to follow. The museum began laying out apples and leaves to lure the ants along.
But soon another problem arose: the gallery, still under construction, was too dry for tropical ants. Therefore, a humidifier was installed behind the exhibits to transport moisture into the showcases.
The path of the ants is simplified, and a rope is strung on the overpass so that the ants don’t have to walk backwards. Another shortcut has the ants go around some aluminum poles.
By mid-April, rows of ants begin returning leaves to their nests. “It felt like the ants were celebrating,” Mr Garrett said.
There is more work to be done. Ants didn’t really like the woven metal that looked promising in the lab, and they kept falling into the moat. Mr Garrett recently made a makeshift “ant filter” out of blackberry twigs to help the insects crawl out.
But the team has now removed the big shortcuts, pushing the ants down more challenging paths. Just a few days ago, the ants finally completed their entire route and even started snaking their way through the elevated maze.
“I know everyone expects the ants to just go straight to the jungle foraging without any hassle, but I think it’s really beautiful how they slowly find their way out,” Mr Garrett said. “We watch them learn every day.”