Fleas can come from a next door neighbor’s dog or cat. They’re usually spread through intermediary urban wildlife, such as opossums or raccoons. Feral animals enter into infested yards, acquire fleas, and eventually spread eggs throughout the neighborhood.
Flea Infestations Spread through Eggs
Infestations Start as Eggs
Most flea infestations begin as eggs in the host’s environment. Animals first acquire fleas as they emerge from cocoons. It’s rare for fleas to transfer between hosts. For example: They don’t often jump from one cat to another.
Eggs Fall wherever Infested Animals Roam
Flea eggs are continually laid on infested animals and dropping from their fur. The eggs fall into the environment, getting distributed wherever the animal wanders. The eggs get clustered in areas the host regularly feeds, rests or sleeps.
Outdoor Flea Hot-Spots
Outdoor hot-spots occur in shady areas where animals rest during the day. Excamples include dog houses, pet shelters, crawl spaces, below decks and beneath vegetation.
Outdoor locations where fleas can survive are limited. Eggs and larvae will die in open areas that are exposed to sunlight or extreme weather. Viable zones for development must be humid, shaded and shielded from the wind.
Upon hatching, the flea larvae must have access to food—the blood feces from adult fleas. Eggs falling from a foraging host have a slim chance for survival, because the eggs and feces get distributed across great distances and it’s unlikely that they’ll fall together. ‘Flea dirt’ is most abundant where the host animal rests and grooms. Thus, resting sites are hot-spots for developing fleas.
Neighbor’s Pet ➜ Feral Animal ➜ Your Pet
Feral and domestic animals both seek shelter under covered structures, such as porches. It’s not uncommon for their territories to overlap. Flea eggs can quickly accumulate and thrive in these areas. And, upon entering these zones, animals can rapidly acquire fleas.
Img 1 Racoons can be hosts for cat fleas, transferring them between neighbors.
Flea infestations can spread from pets to feral animals (and vice versa). Example: Urban wildlife, such as a raccoon, enters into a flea-infested yard. It quickly acquires fleas after taking refuge in an area frequented by a dog. The fleas mate and reproduce on the raccoon as it travels throughout the neighborhood. Eggs fall into virgin yards and the infestation spreads. A cycle of re-infestation continues wherever animal territories overlap.
Many small mammals share habitats with humans and can carry cat fleas. Common hosts are opossums, raccoons, foxes, coyotes, skunks and feral dogs and cats. Sometimes these animals enter into homes through crawl spaces or attics. They may end up depositing flea eggs inside the house before leaving.