alxmh asked 6 years ago
About two weeks ago, our beloved cat Barney died. We’re pretty sure he had fleas, but due to veterinary treatment for cancer, we were unable to deflea him properly. Around two weeks prior to his death, after months of being bitten and occasionally even seeing the odd flea, we decided to have the house fumigated by a professional pest controller. This seemed to get rid of the existing fleas, at least for a while… until today, that is. I’ve found fleas crawling on my legs and my sister has been bitten. I realise now that it was probably a complete and utter waste of time and money having the house fumigated whilst Barney was still alive and playing host to the little critters, but we had no other option. Is it possible that the fleas we’ve seen today could have only just hatched? And will they be able to survive and reproduce without a cat to feed off (we don’t have any other pets or animals)? The main reason I’m worrying is that my friend is a little reluctant to stay at our house until this issue has been resolved in case he unwittingly takes them back home with him. Can this happen? He doesn’t have any pets of his own, so should this be a problem? I’d be so grateful if you could help and put my mind at rest! Another thing, my bed is on the floor, can fleas live inside mattresses? And do sprays such as Johnson’s 4 Fleas IGR spray work? We’ve tried this, alongside vacuuming and sprinkling salt, but it doesn’t seem to be working. Should we bring in a professional again? How long should we expect this problem to go on for?
Adam Retzer Staff answered 6 years ago
Hello,
The adult fleas you are seeing did likely just emerge from cocoons. The bulk of infestations (95-99%) are eggs, larvae, pupae that live in the environment. Many reside in protected refuges (e.g. the base of carpets) where insecticides and vacuums can reach. It is normal to see fleas even after proper treatment. Infestations usually take about 8 weeks to end. This is because all of these immature stages need to mature, emerge, and die before the infestation ends.
The fumigation probably wasn’t a waste, unless an insect growth regulator (IGR) wasn’t used. The two common ingredients are pyriproxyfen (Nylar) and methoprene (Precor). The IGR is effective for environmental control because they last 7 months indoors. IGRs mimic an insect hormone that regulates development. Exposed eggs and larvae aren’t able to mature into adults. Fleas already present and protected in the environment may not be affected. But any new eggs that fall onto the treated surfaces won’t survive. So the current generation should be the last.
Cat fleas (C. felis) make up nearly all domestic infestations. This species can’t survive or reproduce on human blood. An infestation won’t continue or start without an animal host.
Almost all infestations spread when an infested animal enters new territory and flea eggs are dropped there. Infestations don’t often spread from adult fleas hitchhiking on people, though it is possible. Still, without pets at your friend’s place, it shouldn’t be a concern.
Fleas don’t live inside mattresses. But they may develop on the surface of bedding, provided an infested animal rested there. Eggs are laid on the host, but they aren’t sticky and soon fall. So the eggs can end up anywhere the pet accessed.
Any spray with an IGR should work. The IGR is the most important ingredient. Some sprays have it in higher concentrations than others. It probably doesn’t seem to work because of my explanation in paragraph 1 and 2. Young fleas develop in protected micro-habitats where sprays can’t reach. So they won’t be affected. However, any new eggs that fall onto the surfaces won’t survive. Some patience is required with flea control.
You shouldn’t need to hire a professional again. They will likely just apply a similar spray that you are applying (an IGR spray, with an adulticide to quickly kill any emerged adults).
I apologize for the delayed response.
Warm regards,
Adam
