BEVERLY — Morgan Park resident Tim Blackburn was enjoying a lovely picnic with his family last weekend when they were swarmed by hundreds of unexpected guests.
“We just started seeing flying ants stream down the driveway,” Blackburn said. “They were everywhere. They covered people, they covered the driveway and sidewalks, they were in people’s hair, you name it.”
Blackburn and his family sought refuge in the garage until the swarm subsided about 45 minutes later.
The sudden onslaught of flying ants likely means the tiny winged creatures were having their annual “nuptial flight,” according to Andy Suarez, an ant researcher at the University of Illinois.
That’s when some ants stretch out their wings, emerge from their nests and fly around looking for mates, he said.
Ants are social organisms that live in colonies, headed by a queen and maintained by an army of female workers, Suarez said. For most of the season, the non-flying worker ants forage for food and protect the colony while the queen lays hundreds of eggs each day to increase the workforce she oversees.
At certain times throughout the year, the queen’s focus shifts toward laying eggs that grow up to be future queens and male ants that can mate with them, Suarez said. Unlike worker ants, queens and their male partners have wings and will emerge from the nests to mate while swarming in the air, Suarez said.
“It’s a switch from focusing on colony growth to colony reproduction,” Suarez said. “They fly, they find their partners, they mate and they start a new colony.”
It usually only takes ants a few days to fly around and find partners to mate with, Suarez said. There are more than a dozen species of ants in Chicago and each of them takes flight at different times, Suarez said.
Matt Gandurski said thousands of ants hung around his backyard for hours last Sunday, flying in clumps low to the ground.
“It looked like there were piles of dirt everywhere, I thought my kids had maybe been throwing dirt around in the backyard,” said Gandurski, who lives in West Morgan Park. “I went outside to investigate and realized they were alive.”
Suarez said this means Gandurski’s backyard was likely the location of a “mating swarm,” where numerous ants from different colonies congregated to mate.
It’s common for ants to fly in the fall and spring, though it can happen at any time throughout the year. Scientists don’t know exactly what triggers the ants’ flights, but decreasing amounts of daylight and increasing amounts of rainfall might provide “cues” that tell ants it’s time to take off, Suarez said.
“The flights do tend to be coordinated within a species so that when the colonies do release their winged individuals they’ll be able to find partners of the opposite sex from other colonies who are flying at the same time,” Suarez said.
After a queen mates with her partner in the sky, the male ant loses his wings and dies. Then, the queen finds a comfortable hiding spot, usually underground, and begins laying eggs that will hatch a new colony of workers who can renovate her nest, Suarez said.
“It’s so cool to think about how an ant colony is this giant social organism with hundreds if not thousands of workers,” Suarez said. “But, each generation it’s up to a single, very vulnerable individual to start another colony on her own.”
Instead of flying away, many of the ants in Gandurski’s backyard died and stuck to all of his patio furniture. Suarez said this is common because the ants are only able to fly for short periods of time, so many of them die before they’re able to mate.
“They literally all just died right where they were,” Gandurski said. “I’m still in the cleanup process, reclaiming little chunks of my backyard every day. It’s like, if I move a planter there’s just a little ring of dead bugs around it. There wasn’t a centimeter of the cover on our outdoor couch that didn’t have bugs on it.”
The few queens who make it will likely hatch their first workers late in the fall. This allows the workers to start preparing the new colony’s nest before it gets too cold, Suarez said.
The colony “won’t really take off” until the spring, when the queen will ramp up egg laying and “try to get her colony going in full force,” Suarez said.
“Hopefully when people see these queens out and about, they’ll root for them,” Suarez said.
Although the main purpose of the ants’ flight is to produce more ant colonies, their emergence provides a “valuable food source” for birds, rodents and insects ahead of the cold winter months.
“It’s like a giant recycling of resources because all season, ants scavenge and bring resources underground to feed the larvae that turn into the queens who fly out into the air,” Suarez said. “Then other species will eat them, and they’re very protein-rich and just a fantastic food source. It’s a really important pulse of resources.”
The new colonies also help to aerate the soil and are great for gardens because the ants will eat other pests, Suarez said.
This means it’s best to leave flying ants alone if possible, Suarez said.
“I’m really sympathetic to people who don’t want ants in their house, but in general, if you see them out in your yard it’s okay to embrace it as a cool, natural thing occurring outside,” Suarez said.
If they’re flying around your home, a vacuum cleaner can be a good way to get rid of them without using pesticides, Suarez said.
Gandurski said he’s using power washers and “every tool at his disposal” to clear away the dead ants coating his yard. He said they’re “weirdly clingy” and don’t just fall off objects when you shake them.
“It’s a testament to how weird things have been recently that we just kind of took it in stride,” Gandurski said. “My whole family was just like, ‘Whatever, there’s just another pestilence happening.’ It’s 2023, life is weird enough already.”
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