A picture is worth a thousand words, right?
This is my window sill covered in cinnamon.
After it rained, some ants tried to scout out my kitchen. I found them early in their explorations when they were beginning to come in at the back door and window. We have a little mud room out there where we keep the recycling, and the kitchen sink is right by the inner door too, so all those yummy recycling and dirty dish smells waft out and invite the ants in.
I saw them in the window first, and cinnamon is supposed to deter them, so I sprinkled a thin line in the crack of the window sill. That drove a few that had collected in the crack out into the open, and that is when I went ballistic with my cinnamon shaker flinging pie-scented murder all over the place.
I painted around the doors and inside the recycle bin with clove oil. They hate that too. That held the little bastards off until I ran out and got some terro traps.