Oops, Pardon me!
The nest can be a very busy place, especially later in the season as the colony grows. The industrious wasps are constantly coming and going, foraging for food and enlarging the nest. These two Eastern Yellow Jackets bumped into each other just above the nest entrance during such a busy time. One wasp was flying off to hunt as another came zipping back with a bit of food clenched in its mandibles, or jaws.
This image is a crop of the original, which was taken at ½x life-size, as I lay at their nest entrance. In my experience this magnification seems to be the "sweet spot" for best results. It leaves about 16 inches between camera and subject -- which is great for skittish insects... to say nothing of my comfort level with ones that sting! It also gives me more depth of field than taking them at life-size, which means my success rate for sharp images of flying insects is much greater. Plus, it gives me more leeway for timing the shutter release as they fly into the 2 x 3 inch target area. When I tried taking them at life-size, my success rate was bordering on abysmal... half life-size increases it to about one in ten shots!
Thank goodness for digital over film!