Welcome to ‘Ratatouille’: Paris is trying to curb its rat population ahead of the Olympics kick-off as thousands descend on the French capital

Paris has a fabled relationship with rats, as the film Ratatouille referenced.

But unlike the much-loved animated movie, they are not always determined chefs well-versed in French cuisine. Mostly, they are pests whose population has flourished in France’s capital city and have long been the subject of debate.

With the Olympics set to kick off later this week, Paris is trying to limit the number of scurries running about the city as it welcomes visitors for the summer.

"All of the Olympic sites and celebration areas were analysed (for rats) before the Games," the deputy mayor of Paris Anne-Claire Boux, who looks after public health, told Agence France-Presse in an interview published Tuesday .

Rats are a less-than-ideal yet characteristic element of cities like Paris and New York. The French capital, considered the world’s most romantic city, has long tussled with vermin largely because of garbage piling up on street corners.

In 2017, the city implemented a plan to keep rats out of the streets using airtight trash bins and mass extermination. Activist groups even suggested birth-control measures to limit their numbers.

But it has since softened its approach. Between 2021 and 2023, a government study named “ Projet Armaguedon ” (“Project Armageddon”) aimed to examine the environment in which rats thrive while “fighting against prejudices” to help Parisians live with rats.

Last year, Parisian mayor Anne Hidalgo suggested that instead of wiping out rodents altogether, “ cohabitation ” might be a better option.

Paris has a long and dramatic history with rats that dates back hundreds of years. They caused the spread of the bubonic plague (albeit a different type of rat than the one running about streets today) which decimated roughly half of the city’s population in the 14th century. However, rats also served as a critical food source during a famine around the 19th-century Siege of Paris.

Fighting the vermin population is hard work, especially with warmer weather, which makes it more conducive for them to proliferate. But some French cities have managed to succeed. For instance, Toulouse used ferrets to hunt the rodents down, as the traps were only effective with younger rats.

For Paris, the battle looks different. Even though the city will be in the spotlight over the next few weeks for hosting one of the most iconic sporting events in the world, the rats will likely still be part of the fanfare—so long as they remain underground.

"Ultimately, no-one should aim to exterminate Paris's rats, and they're useful in maintaining the sewers," Boux said. "The point is that they should stay in the sewers."

With a single-digit countdown to the Olympics’ kick-off, city streets have been cleaned up and old buildings have gotten a makeover ahead. The team of exterminators helped advise the organizing committee of the Paris Olympics on ways to keep their venues clean, AFP reported.

Separately, Paris also has “ dengue detectives ” on duty to hunt for tiger mosquitoes and prevent a possible outbreak.

Other pressing health concerns surround the Seine River, which will reopen for public swimming for the first time in 100 years . Mayor Hidalgo took a dip in the river last week to tell the world that the water, which had seen high E. Coli numbers until recently, was safe to swim in. She described the water as “exquisite.”

This story was originally featured on Fortune.com