Borax (sodium tetraborate) can be bought from most chemists - or could.
Amongst other things, it is used as a detergent.

Two days ago my son mixed sugar with some of our regular laundry detergent
(because he had heard it contained borax) and applied it to a small ants
nest next to our driveway.
I'll observe effect if any and report back
Terry.
PS. Small blackish ants which seem to be everywhere but rarely come into the
house; rarely even into our below ground concrete unfinished walls basement.
Where however we occasionally see 'wood lice' here called "Carpenters".

it's normally used for
killing mites in pigeon lofts, but it's permanently fatal to ants

Tee hee - as opposed to temporarily fatal...? ;-)

Martin:
Hmmm!
Probably 'Overkill'!
Anyhow our R'anting should now be over? :-)