Cats stay outside but still seeing fleas inside

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QuestionsCategory: Flea InfestationsCats stay outside but still seeing fleas inside
Thmama3 asked 4 months ago

Hi thank you for this site! I tried to look at all the questions and still didn’t find the answer I’m looking for. We have cats that stay outside only. We have been dealing with fleas for quite awhile even inside the house. The situation inside has gotten drastically better after vacuuming like crazy but I still find fleas from time to time (usually biting me as I am the only one in the house that gets bites)! I read about human fleas in one of your answers and I’m so freaked out that could be the problem but surely it’s not since I have seen fleas on our cats before? Why am I still seeing fleas in my house if that cats never come inside? It literally seems they jump off the cats onto me and I bring them in (even though I’m usually only outside long enough to feed them). So will continuing to vacuum eventually solve the problem? I’m not very fond of chemicals and don’t feel the problem is bad enough to resort to that. Thank you so much for your time I know this was a long one!

1 Answers
Adam Retzer Staff answered 4 months ago


That sounds like a strange situation. I can think of a few possibilities:

(1) You are bringing in fleas from outside. They may developing in the yard, and upon emerging from cocoons, the adult fleas jump onto you. Still, this is odd, as you would see fleas on your outdoor cats (or am I confused, and you have seen fleas on your cats? Human fleas (P. irritans) infest dogs and cats, the name “human flea” is just the common name. The same goes of cat fleas (C. felis) and dog fleas (C. canis).)

(2) You are dealing with human fleas (P. irritans). This is a fairly rare species, but it can survive and reproduce on human blood. See this question’s answer, where I described how to identify flea species.

(3) You are dealing with mice or rats in your home, and they are infested with a species of rodent fleas. If true, the flea problem won’t resolve until the rodent problem is resolved.

Though you don’t want to use chemicals, it may be a good idea to apply an insect growth regulator (IGR) inside. IGRs mimic natural insect hormones that regulate development. They will prevent eggs and larvae from reaching adult. And they remain active indoors for 7 months. IGRs are considered safer than traditional insecticides, because the work specifically on insect endocrine systems. Martin’s IGR comes in a good size for indoor use.

If your outdoor cats have fleas on them, it may also be a good idea to treat them somehow, as to ease their discomfort.

Since you are dealing with a bit of an unusual situation, it may be a good idea to hire profession pest control to come take a look in person.

I hope this was useful.

Thmama3 replied 4 months ago

Thank you for your answer! Yes I have seen fleas on my cats and have tried to treat them but one is pretty shy and I can’t get too close to him. I’m certain we do not have a mouse/rat problem in our home. I found another flea on me today and tried to examine it to see if it’s the human species but still not sure if it is. My question is this, if my cats have the human flea species and that’s what is coming in wouldn’t it be more likely for them to multiply like crazy in my home while feeding on me? I ask because the problem is so much better right now than it was. I’m sorry for taking more time and space. Thanks!

Adam Retzer Staff replied 3 months ago

It could be more likely that they are human fleas if the cats never come inside, since they are the only species that can survive and reproduce on human blood. Other species wouldn’t be able to easily get indoors unless an infested host was there, but adults could hitchhike in on clothes.