• The parasitic insects are visible to the naked eye and live in dark spaces such as cracks in beds, sofas or — as seen in recent reports — fabric seats in public areas.
• They cannot jump or fly but spread on clothes and other items such as bags and suitcases.

France's transport minister on Wednesday urged for calm amid widespread reports of bedbug infestations in the capital and other cities, as he said more could be done to tackle the scourge.

"Along with transport operators, we will provide even more efficient solutions," Clément Beaune told reporters after holding an industry meeting, adding that discussions would be held with cleaning companies regarding innovations in the sector.

"There is no [bedbug] resurgence, we must not fall into madness," he also said, according to French broadcaster BFM TV via a CNBC translation.

It comes after videos appearing to show bedbugs, or "punaises des lits," on the Paris Metro, high-speed trains and at Charles de Gaulle Airport were shared widely on social media. Sightings have also been reported in homes, cinemas and hospitals.

The French environment ministry says bedbugs have made a resurgence since disappearing in the 1950s due to international travel and increased resistance to pesticides.

The parasitic insects are visible to the naked eye and live in dark spaces such as cracks in beds, sofas or — as seen in recent reports — fabric seats in public areas. They cannot jump or fly but spread on clothes and other items such as bags and suitcases.

They feed on blood and can cause severe itching and allergic reactions in humans.

Advice for their removal includes reducing home clutter, washing clothes at high temperatures, heat cleaning furniture and carefully checking clothes and beds for the telltale black bugs and their droppings. However, they spread rapidly and are notoriously difficult to get rid of, generally requiring professional treatment.

Concern over their spread in Paris has mounted in recent weeks amid the social posts and media reports.

Paris Deputy Mayor Emmanuel Grégoire wrote on social media platform X that "no one is immune," and said health authorities and local communities needed to work together on prevention. Grégoire said lower-income households needed to be supported with the costs of dealing with an infestation, which Paris has begun.

However, experts note that a rise in the number of bedbugs is common in late summer due to the rise in travel, and that this trend is not confined to France.

Bedbugs affected roughly one in 10 French homes between 2017 and 2022, according to scientific agency ANSES, which says there has been an increase in recent years.

The New York Health department describes bedbugs as "common" in the U.S. city.

"We do know that bed bug infestations can spread to new locations very quickly and, once they have, this pest is difficult to control," entomologist Jim Fredericks, senior vice president of public affairs at the U.S. National Pest Management Association, told CNBC.

"Bed bugs are great 'hitch hikers,' allowing them to travel long distances with people ... France has seen a significant increase in visitors as a result of Fashion Week in recent weeks, which provides an ideal scenario for bed bugs to be transported from one location to the next."

Bedbug populations have risen dramatically over the last two decades, Fredericks said, swelling during the summer months.

Natalie Bungay, technical manager at the British Pest Control Association, also said bedbugs were a global issue that tended to intensify during busy travel periods.

"Bedbugs have been a problem in the U.K. for many years and are a public health pest that is notoriously difficult to treat," she said, with London and large cities particularly impacted.

"We're not aware of any unusual increase in [U.K.] bed bug activity – there was a dip during Covid-19 due to the lack of global travel taking place, so any increase now could just be trends getting back to normal now that everybody is moving freely again," she said.