Bit wary of ant powder inside the house, keep the cat and small humans away from that stuff, there used to be a spray called Kybosh, no idea what was in it but it melted them, the spray was really powerful so one blast would go into every crevice, a second blast later was usually enough, never did work out where they went, think it dissolved them, and you need to remember to open the windows at the same time incase it killed you too, no idea if it’s still available but there might be similar.
Nicotine is/was(EU banned it) the traditional fumigation method, so if you know anyone that smokes get them to have a fag and blow the smoke in, smoke them out, this one was not properly thought through really.