As a cat owner I thought I would share a dreadful experience from a couple of years ago....    We owned a beamed cottage and had tongue and grooved wooden floors...   we had two cats which we failed to de flea properly over the winter months (used bob martins products)   We didnt have scratching cats and neither of us were affected ( I have been in flea infested houses through work and been eaten alive before- they seem to like me)  Anyway - we had to move house so my partner took the cats and I let the house to a friend as a favour..   It was about June/ July time...     I had a phonecall saying there were fleas running about on the floors...   I got bombs and sprays and powders but they just kept living (and unbeknown to me hatching!)     Then I called a pest control man who sprayed the house with a well known formula...     the fleas survived- seems they become immune to certain chemicals...    So I rang a specialist company called IGROX, they got rid of the flea in one day!  Seems that the fleas lay eggs which on hard floors can drop down the gaps and lay dormant for years!!    GRIM!    The fact that the cats  (the hosts) had been taken away at the same time just added to the embarrassing nightmare....    Of course we have gone back to frontline and carpet which is expensive but it works!     I have never been so ashamed in my life but I guess we deserved it for not using proper products!