I understand that it can be particularly hard to do so when you have kids at home, where they tend to leave food crumbs almost everywhere. Here, you must make it a point to train your children not to leave food around and there would be a need for more frequent checks on the area. Or, designate an 'eating place' so that all spills are concentrated in the small area so that it is easier to clean up.
Ants usually come in through a cracks or openings. Try your best to find where they are coming in at and close it up. Caulking works really well to seal up cracks and other openings where they may be getting in. You may have to do some investigating because they can enter through even the smallest of areas.
After you have done your part to make your home less inviting, you can do a few more things to get rid of ants to supplement your efforts in clearing them away. There are a few common household items that ants hate and will shun away from them. Most of them are natural and you can easily find them. First, they can not stand baby powder, so if you sprinkle some wherever you have seen them it should make them take leave. They also do not like vinegar, which you can spray in the areas where you have seen them. You can also sprinkle cinnamon, black pepper and bay leaves around to keep them out.
Getting rid of ants is actually quite simple, using items from your kitchen. As long as you take the precautions to prevent them form coming back - cleaning up food and sealing entrances - you should be able to try some of the homemade ant repellants and be able to live ant free.