A study published in the journal PeerJ , conducted by a researcher from the Institute of Systematics, Evolution and Biodiversity (ISYEB) at the French National Museum of Natural History, in collaboration with a researcher from James Cook University in Australia, reveals that domestic animals are involved in the transport of an invasive flatworm species in France.
Terrestrial flatworms (Platyhelminthes) are invasive species that primarily spread through the transport of plants, largely driven by human activities. However, one question remained unanswered: how do these very slow-moving animals manage to colonize neighboring gardens?
By analyzing more than twelve years of reports collected through citizen science initiatives in France, the researchers uncovered a previously unsuspected role played by domestic animals. Flatworms were indeed found attached to the fur of dogs and cats.
Surprisingly, among the roughly ten flatworm species that have invaded France, only one appears to be involved: Caenoplana variegata . Its particularly sticky mucus, associated with its arthropod-predator diet, as well as its ability to reproduce without a partner, facilitate its dispersal.
Given the considerable distances traveled each year by domestic animals, this mode of transport may significantly contribute to the global spread of certain invasive flatworm species.
PeerJ
Cats, dogs, and sticky worms: invasion by land flatworms (Geoplanidae) is facilitated by household pets
10-Feb-2026