When ants establish a colony in your house, they can be very hard to get rid of. Nothing is worse than taking a drink of cola only to find an ant crawling up the side of the can. Even worse, they quickly infest any food left out, including pet food. Before calling an exterminator or putting dangerous poisons around your house, try these natural approaches to ridding your house of ants.
Find the colony and kill the queen. The queen is usually buried under a pile of ants. She's larger than the other ants, and usually lighter in colour. If the queen is dead, the colony will disperse.
Destroy the nest. If you can find the nest, pour boiling water over it. Look for nests outdoors near your house, too, as the ants may be coming in from outside.
Block the colony's entrance to your house if you can't reach the nest. Find where the ants are coming from and block the hole with caulk or some other sealant, if possible.
Sprinkle ant deterrents at the entrance to the colony if you can't block the hole where the ants are coming from. Try salt, talc, cinnamon, black pepper, cloves, mint, or bay leaves--ants don't like the smell of these. Corn meal will kill ants when it swells in their stomachs. If they're coming from an area children and pets can't reach, cayenne pepper or diatomaceous earth are effective deterrents as well.
Kill the scouts. If you see a single ant crawling around, it's probably a scout. If it gets back to the nest, it will alert the other ants that there is food, and they'll all come out to get it.
Erase the ants' scent trails. Ants marching in a line are following a trail to food that a scout left, and without the trail, they can't find the food. Spray along the trail with water mixed with two tablespoons of bleach or vinegar.
Keep home surfaces very clean. Sweep and vacuum regularly and wipe counters, tables, and floors with the vinegar or bleach solution mentioned previously. Don't leave dirty dishes in the sink and keep the sink dry and clean. Any food crumbs, water, or spills of sweet liquids will attract ants. Conversely, if they can't find food, they're likely to look elsewhere.
Put pet food in the fridge or in a sealed container at night to keep ants out of it. Store sugar in the fridge instead of the cupboard or in a sealed container. Ants can get into sugar in boxes or bags.
Keep trash outside and empty the trash often. If trash is left indoors, seal the bag with a rubber band or twist tie to contain the scent and make it harder for ants to find.
Ants are very hard to get rid of, and it can take several weeks to destroy established colonies. If ants are still a problem after you've tried all these steps, you may have to use poison or call an exterminator.