Grrrrr!!! Got a serious ant problem in our living room, how do we get rid of them?

Think they must come out at night or something as my partner came down this morning and reckons he killed around 40/50, then about half an hour ago i came down and got about 30, its just a nightmare and i dont like to let my little one crawl around in here now. What can we do, as its really stressing me out now, i hate any creepy crawlies!