Fig. 6. Frequency distribution (%) of the duration of trophallactic interactions performed by food-receivers interacting with marked bees (see Materials and methods for details). Data from the constant series. Results are presented for each of the two different reward rates offered at the GF (grey bars: 3 µl min^-1, N=422, 105 food-unloading events, 17 marked bees; open bars: 90 µl min^-1, N=266, 101 food-unloading events, 15 marked bees).