I had ants that were in love with Purina dog food. I made a bait from 1 part
boric acid and 12 parts Purina. It didn't kill all the ants but it killed the
ones that liked Purina. They are still walking around in the house. Ants may
have separate food streams in the same nest. A bait will only affect that food
stream. In most cases that is all you need but if you really have a lot of ants
it may not really mean that much.
I see the same thing with fire ants and baits like Amdro. You can move them
around and disrupt them but they don't go away. The only people here who don't
complain about ants have a service come in once a month and spray a ton of
chemicals around the house and yard. I can still point out ants to them.