Last summer I set out a beautiful spread and watched a line of ants march up the table leg within ten minutes. By the time anyone sat down, the potato salad had a fly circling it like it was the main event.

Here’s what actually worked this year, tested over three separate picnics.

Keep food covered, always

Mesh food covers are the cheapest fix and they let air through so nothing steams and gets soggy. The minute a plate isn’t covered, that’s when the bugs move in. Keep lids on drinks too, or use cups with straws.

The other stuff that helped

• Set up away from trash cans and standing water, which is where the bugs already are.
• Wipe up spills immediately. A sweet drop of lemonade on the table is a bug beacon.
• Put a small bowl of vinegar or a few cucumber slices at the table’s edge. Flies don’t like either.
• Keep food cold. Bugs are drawn to warm food way more than cold, so ice trays under the bowls do double duty.

The difference was night and day. We ate without swatting, and for a picnic that’s basically a win.