How do I find where ants are coming from?

What does an exterminator do for ants?

Seal cracks and crevices around foundation

Avoid vegetation contact 

Peg your potted plants to prevent moisture barriers conducive to ants

Seal cracks and crevices around the foundation 

Seal the cracks and crevices to keep the excessive moisture out of the cracks conducive to ants

Keep excessive moisture out of cracks and crevices