[Margaret Pilkington]

The flea population had exploded this year due to the warm weather. My husband was sat outside enjoying the sunshine a couple of weeks ago and two jumped onto him.

I used frontline on Gizmo(rest in peace lad) but he still got them......so after every walk I combed him with a flea comb and drowned the little invaders.

Fleas spend most of their lives off the animal, but they jump on for a feed...they are sensitive to heat and vibration so that they know just when a meal is approaching.
Flashy is right, the fleas will not die until they have fed..but this is no good if you have a dog who has a flea allergy....the flea spit causes immense irritation, and the dog will scratch purely because of this.
Get a steam cleaner(you don't have to pay a lot of money for one).......steam all the places where the dog goes and where he sleeps......and comb your canine friend each time he comes in from his walk.