How Fleas Survive the Winter in Your Home

By Chris Williams on October 25, 2013.
Fleas on house dog


How come my dog has fleas even in the dead of winter? Aren’t all of the insects outside dead, so where is he picking up the fleas?


You won’t like this answer. Your dog is almost certainly getting his winter fleas from your own home. Our biggest problem in flea control is getting customers to understand the flea life cycle and that flea control is a two-part process.

Fleas can continue to reproduce and reinfest your dog very happily all winter long inside your home. Your dog doesn’t have to go outside to be attacked by fleas. All he has to do is lay down on his doggie bed inside. Here’s why:

  • Adult fleas spend all of their time clinging to hairs on the pet and feeding on the pet’s blood. Female fleas lay eggs that randomly fall off of the animal, ending up wherever they land. It stands to reason, that there will be more flea eggs in places where your dog spends more of its time — maybe on the sofa, on the fireplace rug, in its dog bed, or even in your bed.
  • When the eggs hatch, the legless flea larvae feed and develop right where they are. Their food is mostly feces dropped by the adult fleas which is rich in dried blood.
  • When the larvae are fully grown, they pupate, again in pretty much the same place where they hatched. When the flea emerges from its pupal cocoon, it is a fully formed adult flea looking for an animal to feed on. As soon as your dog passes by, or lays down, the newly emerged flea will hop aboard for a blood meal. Then the cycle continues.

This is why we always encourage our customers to be sure that their pets are treated at the same time that we are treating their homes. Our treatment kills the flea eggs and larvae in places where they are developing in your home. But our treatment is not going to kill the adult fleas that are on your pet. That requires a separate on-animal flea treatment. Conversely, when people treat their pets for fleas but don’t have an in-home treatment to kill the developing larvae, new adult fleas will eventually hatch out and reinfest the pet…or bite the people.

Fleas don’t necessarily come from outside, although in warm weather, pets can be infested by fleas that are living outdoors. In winter, most outside fleas will die. Unless your dog is treated for fleas, his fleas will actually help to restart the outside flea population come spring. In fact, flea control is sometimes a three-part process, because in addition to treatment of the pet and the home, we sometimes need to treat the yard for fleas as well.

Photo credit: cyborgsuzy / Foter / CC BY-NC



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