Residents have told how hoards of the winged bugs have invaded gardens and homes across the city during the summer heatwave.
Some have described their attempts to wage war on the insect armies.
But an insect expert from Leeds University said the swarms – which happen each year – are nothing to worry about.
Sophie Evison, a researcher in the biology of social insects, said: “It shouldn’t be surprising – it happens every year.
“This is a mating flight that they do once a year around July and August where colonies co-ordinate the mating so that they cross genes. They usually last for a couple of hours and then they’re gone.”
Mother of three Elaine Hudson, 42, of Kings Road, Hyde Park, said she was confronted by thousands of flying ants after cleaning her kitchen.
“They were all over the surfaces, on the fridge, crawling across the floor – they were on me,” she said.
“It was horrendous. I started screaming, my kids started screaming. I suffer from asthma and it nearly brought on an attack.”
Flying ants – winged members of common black ant colonies – take to the air once a year in what is known as the ‘nuptial flight’, when the queens and males mate.
The males die after mating, with the queens starting new colonies.
Facebook users have told of their encounters with swarms of the insects.
Danielle Holmes-Thompson said: “We had to come inside the house as there was a plague of Biblical proportions in our back garden in Leeds 14.”
Melissa Smith added: “I’m sick of seeing them.
“The hole of Robin Hood is full of flying and normal ones, they’re even living in walls of our house and we can’t sit in garden cause there are 1,000s of them.”
Sonia Fell, of Methley, said: “My small bedroom was full. Two tins of ant killer to get rid. Thank god - must have been 100 or more, could not sleep that night.”