If you have ant problems, sprinkle cinnamon around the window sills and door jams - around the kitchen counters - and the ants will not only avoid crossing the cinnamon, it will make them not want to come back. And! Then your kitchen smells like you've been baking, not ant poison.
I had never heard of this before, but my friend's kitchen is sprinkled in cinnamon and she has nary an ant brave enough to cross a line. Now I don't know how long she'll have to keep things sprinkled or exactly the biology of why ants have a cinnamon aversion.
If you're that smart, dear entomologist, explain it to us in the comments.