1. Killing Roaches with Borax
Borax can be toxic for humans and animals, so you need to be careful how you use it. It is best to sprinkle the borax on top of your cupboards so that no one but the roaches comes into contact with it.
After they walk through this deadly powder, they will take it back to their nest and inadvertently wipe out their entire colony. Alternatively, you can use catnip as a natural cockroach repellant.