Flying ant day always came before Lisa’s birthday. As a child, the ants would signify her imminent elevation as she caught up with her classmates, in age if nothing else. But then her older brother would fry them with a magnifying glass, and she would again feel unsure, locked out of a world guided by rules she couldn’t yet imagine.

The year of her wedding, however, they came late. The ants’ weak flight was no match for the incessant rain, and so they stayed trapped below ground as her birthday came and went. Her friends grumbled because their fractious children were trapped inside, her colleagues grumbled because they couldn’t do their fieldwork. Finally, on her wedding day, the ants swarmed. The heat which caused the men to sweat under their suits released the mating swarms from their nests. Fat queens and tiny males landed on her wedding dress, and her new mother-in-law believed she’d seen an omen.

“Get them away!” she had shrieked as she batted the ants off the ivory dress as if they were flakes of ash.

Two years later the ants really were an omen. On the day Lisa came with her husband to announce their move abroad, the ants swarmed out of her mother-in-law’s patio as a seething mass, reminding them of their differences.

The three of them had tea on the terrace, with stale cake that tasted like tissue paper. The pleasantries quickly faded, and a wood pigeon cooing on the roof was all that was left of conversation.

When he had made it half way through his cake, John laid down his plate. “Mum, we’ve actually got something to tell you.”

His mother, Penelope, stopped stirring her tea and turned to Lisa, her puffy cheeks pushed back in a delighted smile.

“As you know,” John said, “Lisa’s contract is coming to an end, and she has been given a new job offer.”

The smile disappeared.

“An offer which I accepted.” Lisa gave John a severe look – he’d made it sound as if there was room for negotiation.

“Congratulations,” Penelope said tersely. “And what is it to be this time?”

“Oh, ants again.”

Penelope looked around her, as if checking for stray members of the ant wedding party.

With a glance at Lisa, John delivered the punch. “The thing is, it’s in America.”

“Well, you surely can’t be considering that!”

“Actually, Mum, we are.”

“We have considered it,” Lisa corrected. “And decided this is for us.”

“But how long for? Can John get his job back when you return?”

“It’s an assistant professorship.”

“What does that mean?”

“It means there’s tenure track – the post could be permanent.”

Penelope’s face contorted as she tried to decide which emotion to show – anger? fear? loneliness? She wiped her eyes melodramatically, before there was even a tear. “You’ll leave your home behind?”

“We’ll never leave it behind, Mum, we’ll just live somewhere else.”

“We’d welcome you for a visit.” Lisa reached for a second slice of cake, both as something to do and to look polite.

“I need to be invited to visit my own son’s house? A visitor? Lisa, you have no idea what it’s like...”

“It’s not Lisa’s fault. There aren’t jobs like this for her in England, and I want to go with her.”

It had been John’s idea in the first place, but he didn’t seem keen to own up to that now.

“This is your home, no job can change that.”

The first breeze of the afternoon brushed Lisa’s arm, and was shortly followed the arrival of two queen ants. One landed on the teapot, one on the decking. Penelope reached forward to protect the teapot, but Lisa stopped her.

“Wait – I’ll take that for genetic analysis.” She rummaged in her bag for two sample tubes and gently flicked a queen into each of them.

It wasn’t for genetic analysis, it was for effect. There was no genetic difference between queens and workers – the difference was in the way they were raised – and she’d already sampled workers from that colony, discreetly, when she was in a tactful mood.

The desired effect was easy to come by.

“Can you ever focus on the important family matters, or do you always have to put science ahead of us?” Penelope shook her head, then rose from her chair and walked to the house.

Alone, John and Lisa looked at each other.

“Why did you have to do that with the ants?” The soothing lilt had gone from John’s voice.

“It was the quickest way to end the argument.”

John nodded in reluctant understanding. “I’ll go and speak to her.”

“OK, but don’t let her talk you out of it, it’s not fair to make her think she could still stop us.” Again, the woodpigeon filled the silence. “She’ll try to manipulate you. Don’t let her.”

John let his hand rest briefly on Lisa’s shoulder before he followed his mother inside.

As soon as he was gone, Lisa went to examine the ant colony, which was now taking to the air in a constant stream. Along the garden path, some of the mated queens had landed then chewed off their wings. Free of this burden, they ran erratically along the paving slabs to look for somewhere to nest. Lisa crouched down, watching them. Once they’d made their home, they were stuck there for life.

The sound of raised voices came from inside the house, although she couldn’t make out any words. The arguments wouldn’t be new; they’d started when a 17-year-old John had announced his plans for university. An emotional Penelope: ‘I’m alone’ ‘this is where you belong’ ‘I cared for you, gave you everything’... It wasn’t that Lisa didn’t feel sympathy, just that she couldn’t live her life on her mother-in-law’s leash.

A frantic queen ran over Lisa’s foot then disappeared under a terracotta plant pot. Lisa knew she would have to use most of her stingy annual leave allowance to fly to the UK and visit John’s mother and endure her passive-aggressive conversation. Perhaps the ants could let her keep calm, help her relax into the daughter-in-law act. She could deliver a parting blow to Penelope that would provide her with a glimmer of interest while she visited. She surveyed the edge of the path. Seven new colonies in seven plant pots, if she could just start them off by adding new queen. How many of the colonies would survive so close together?

Feeling the burn of the sun on her neck, Lisa collected wingless queens one by one. At the edge of each pot she used her finger to make a small hole in the soil, for the queen, if she wished. The soil was moist, rich with compost, perfect for digging. Then she upended the lid of each sample tube and freed its regal occupant. She stood up and surveyed her work, smelling the lavender from one of the pots.

Brushing the dirt from her hands, she headed to the house. As she entered, John looked at her with exhaustion, Penelope with resentment.

Lisa smiled at them and came to stand next to her mother-in-law. “Penny,” she said, “we’re still your family.”