We spent quite a lot of the last two days battling ants. Although we've tried most of the eco-friendly methods mentioned here, and we thought they'd worked, the irritating insects returned. It turns out that the other tenants on our property are experiencing the same problem -- perhaps as the result of ant nests being disrupted during recent construction? -- and our landlady is going to order several AntPro Bait Station Kits. AntPro Liquid Bait Stations are placed around the perimeter of the residence. There's a stake that keeps the station secure in the ground, and the station has a lock so that animals and children can't get to the bait. The liquid bait contains an attractant to lure ants, plus a low-toxicity, borax-based ingredient to kill the colony and the queen. We're keeping our fingers crossed. $44.95 (ouch) at Gardener's Supply Company.