At PEST UK we often get Estate Agents and Landlords phoning us with flea problems in empty houses. Fleas in property that is unoccupied can present a problem.
The problem is this: In ‘normal circumstances’ a flea treatment will take 2-3 weeks before the fleas die out, although this time frame is dependant on the house being occupied with plenty of movement within the house, the house being kept warm and well ventilated (this is to reduce humidity which makes the fleas and the larvae more susceptible to insecticide) as well as being occupied by people or pets.
As with a lot of blood feeding insects, fleas have the ability to lay dormant for a long time. This is because they may have to wait a long time for their host animal to arrive but as soon as the host animal arrives they must be ready. The lifecycle of a flea in brief is an egg, a maggot like larvae, then it pupates before emerging as an adult. While in the pupa stage the larvae turns into the adult but waits for the stimulus of one or a combination of warmth, movement and carbon dioxide before coming out of the pupa was. It is this adult flea in the pupa case that causes problems in unoccupied properties. This flea is waterproof and is unaffected by water based insecticides.
So a house had pets. The owners weren’t bothered by fleas, as in a low level infestation fleas won’t bother people as long as they have a supply of food from their host (usually a cat but sometimes a dog). The people and pet move and the fleas in the pupa stage wait. An estate agent or landlord arrives with prospective tenants and fleas emerge and start jumping on the visitors looking for a meal. Even if the house is then sprayed there will still be problems because the fleas that have come out of the pupa cases will die (in time) once they have crawled over the treated surfaces but there still will be a high percentage that have not emerged. This is a factor that a lot of insects in larval stages have, staggered emergence. This protects the species and makes survival of some more likely.
There is an oil based insecticide called Permost Uni that will penetrate the flea pupa case. Unfortunately, because it is oil based it will damage carpets and may even require more than one spray. It is also much more expensive.
If you want advice or a treatment from PEST UK on fleas or any pest control related matter then please call us on 0330 100 2811 or 0800 026 0308
Prices for flea treatments. Cost for a guaranteed flea treatment for up to a 3 bedroom domestic house is £65.00 + VAT. The cost for a single spray using ‘Permost Uni’ for up to a 3 bedroom House is £100.00 + VAT (Permost Uni works very quickly but is oil based and may damage carpets).