"Borax solution ants can be killed using various methods. One way is to mix sugar and borax in a large jar, then pour in warm water and stir until the sugar and borax are dissolved. Soak several cotton balls in the borax solution, then set the cotton balls near where you've been seeing the ants. The sugar will attract the ants, and the borax will kill them.0 Another method is to mix one teaspoon of peanut butter with two teaspoons of borax and stuff the peanut butter-borax mix into a plastic straw, then place the straw next to the ant-infested areas.2 Borax has a low toxicity rate for humans and pets, but it's very fatal to ants once they consume it. Ants that eat a borax bait will typically die within 24-48 hours. Foraging worker ants carry the bait back to their colony to share."