with ants.... you have to be real clever...
because they are smart bugs... and the professionals ...even with all of
their sprays sometimes miss the main nest... like here for example ....the spray guy comes and afterwards......... i had more ants...
somewhere on your place....there is wet wood... it's generally on the north side of the house where the sun doesnt dry it sufficiently.
i found a spot where the carpenters had doubled up a some floor joists
underneath the deck... and to look at it... not much signs of ants...
inside or between those two [always damp] floor joists there was a huge colony with a thousand baby ants being created.