Benning style swim in traps are used to sample duck populations. I used them during my time banding ducks. We first baited a site with barley for several days, and once the ducks were acclimated to that site, we erected the trap.

It consists of a vertical mesh net fashioned in an oval shape with the two ends being curved inwards at the bottom to allow the ducks to swim into the barley feed. As the ducks swim outwards to escape, they reach the inset areas and are forced to bridge the gap and hit the other side of the oval wall. The top is also covered to keep out birds of prey.

My team also set out lethal grip traps for mink and raccoons on predatory paths. This helped limit the morbidity of our Benning traps.