Mix sugar with Borax 20 mule team and place wherever you see them. Make sure it's mostly Borax. They will mistake the sugar for Borax and take it back to the nest for grub later on. Then they will be in for a rude awakening. As they eat the Borax, they will die. Soon all of them will be wiped out. It takes less than 2 weeks. And they never come back.