Top (A), cross-sectional (B) and three-dimensional (C) views of the experimental setup. The fan (a) drew air (~130 L/min/tent) from the three tents (b) to the outside environment via PVC pipes (c), trap chambers (d) and central choice chamber (e). Each trap chamber contained a collecting cage (f) into which an exit trap opened (g). The fan pipe and release cup (h) were fitted to the top and bottom of the choice chamber, respectively. Diagrams are not shown to scale; all dimensions are in centimeters.