And now drones will take to the skies in Cannes in an attempt to measure and ultimately destroy the nests found in the city.
The 20 Minutes website reports that Inra (Institut National de la recherche Agronomique) will use the drones to spray biological insecticide directly on the nests, with scientists saying now is the best time of year to tackle the caterpillars as they are still young.
Helicopters have been used in the past to spray wide areas, but this technique is now banned, and so the drones will have a lance attached to the body of the machine that will allow a pilot on the ground to guide the drone close to the caterpillars and target the nests.
The pine processionary caterpillars usually fall from the trees in April and it is when you will see the characteristic long lines as they follow each other nose to tail.
And while that is a view of nature to behold, the pine processionary caterpillar has a horrible 'feature', the small hairs on its back are poisonous and can be a terrible irritant if touched.
But cats and dogs are particularly at risk as the fine hairs can become embedded in the mouth, or stomach, and if not spotted quickly and dealt with by a vet, can prove fatal.