I haven't tried this, but am assured it works.....
You mix borax powder with vanilla sugar.
The vanilla sugar has to be the real deal and not immitation vanilla.
The scenario is that the ants take the small grains back into their nest and the borax kills the whole colony.
Apparently, the ants love the vanilla and sugar.
Supposedly great for other denizens.
For cockroaches, use vanilla sugar and plaster of paris.
When the cockies eat the mix the gastric juices mix with the plaster of paris and sets in their stomach, blocking the works and killing them.
Worth a try.