The middle chamber also had bark chip flooring but both ceiling and walls were plywood. A wooden divider (150 × 80 cm high) ran two thirds of the way through the centre of the chamber, creating a ‘U maze’ between the entry tunnels from the left and right chambers into the middle chamber; a seed tray was positioned opposite the divider (Fig. 1). The entry tunnels were also fashioned from plywood (31 × 10 × 10 cm high) and were the only points of entry to the middle chamber. Within the middle chamber, three LED lights (one above the seed tray measuring 75 × 7 × 6 cm high, 19 watts, 220–240 volts; and two over the arms of the ‘U’ maze measuring 135 × 7 × 6 cm high, 41 watts, 220–240 volts; Planox Eco, Rudolf Zimmermann, Bamburg, Germany) were suspended from the ceiling (150 cm above the seed tray surface and 88 cm above the surface of each arm) so that light projected at an intensity of c. 1000 lux onto the floor of the middle chamber.