The easiest way to kill the fleas harbouring in the carpet of the house from where Tiddles scratched them and the little bugger bred and multiplied? "Quick Henry - the Flit!" is not the answer. Nor is getting the pest man in with his goggles and mask and his jolly toxic sprays.
Latest research seems to say - vacuum the little sods. Kills them dead. Apparently. Hell, I say - why stop there? Vacuum Tiddles too!