Everybody loves a picnic, including ants. Those of us who walk on two legs generally prefer not to share a meal with those who walk on six. You don't need to resort to chemicals in order to find a little picnic peace; instead, just ask:

For our goodies you may yearn-
Sister Ant, please wait your turn.
Don't rush in to steal our food,
There's no need to be rude.
We won't eat up every crumb,
If you're patient you'll get some.
We will leave them when we're through;
We'll leave a picnic just for you.
It's that easy to gain insect cooperation.