Attack fleas on two fronts: on your pet and in the house. For every one flea on the pet there will be hundreds of immature fleas in the carpets. Fleas like dark, dusty areas - under sofas and beds are favourite spots.
Buy a product from your vet to treat the house. The safest and most effective contains a flea hormone, methoprene, that interrupts the life cycle of the flea. Spray the inside of your vacuum cleaner with this, so that any fleas and larvae will be killed when they are vacuumed up. Respray the new bag when you change it.
Spray every room that the pets have access to. Do this twice yearly. Concentrate your efforts around the skirting boards, and under low furniture, and then do a big zigzag from one end of the room to the other to treat the carpets. This spray is not too poisonous for humans, but keep children out of the treated room for half a day.
An anti-flea spray to treat your animals is also available from your vet. This is toxic in large quantities so follow the instructions on the can carefully. Spray pets outside to reduce the amount of spray you inhale.
Fit a flea collar to your pet.