I was in the field a few weeks ago. I'd set up my individual tent in what seemed like a good spot. I went a week with no issue. On the last day, as I went to tear down, I lifted my rain fly and found... ANTS!!! Hundreds of red ants. I emptied a bottle of deet onto the tent, emptied my gear onto the ground and repacked piece by piece, shaking and wiping them out as I went.
Sad that I had to waste a bottle of deet. But equally important as insect repellent, knowing how to avoid the insects! I parked on an anthill and didn't even realize it.