Sprinkle a combination of bicarbonate of soda and black pepper wherever they gather. They can't stand it and will soon vanish. Sage sprinkled in cupboards is also an effective deterrent. Bone-meal sprinkled around the outside walls of the house and throughout the garden will drive ants away.
Dissolve 3 tablespoons of sugar in I cup (250 ml) of warm water, allow to cool, then stir in I tablespoon of bicarbonate of soda. Store the mixture in a bottle in the refrigerator until needed.
Put bottle capfuls on ant nests and trails - anywhere ants gather, including the inside of the house - and cover if wet. This type of bait works on insect's body heat. As they feed on it the body warmth makes them explode. This bait is particularly suitable for indoor use. Mix 2 cups (500 g) of sugar and 2 tablespoons of borax together then dissolve the mixture in I cup (250 ml) of water. Pour into glass jars loosely filled with cotton-wool. Punch holes in the lid and locate wherever you find ants.
If you feel that you must destroy the nest, try pouring boiling water, mixed with a little detergent, down it. Repeat this every few days until the nest is evacuated.