I have been finding black ants in random rooms in my house. On walls and/or floors.
I called exterminators and they want >$350, which I can't afford right now. They claim they are going to lay bait and then ants will take it back it to the colony to kill them.
Is there an acceptable DIY way to stop them from coming in to the house without using those cheap hardware store traps?
What checmicals can a homeowner use?