Feeding activity was in general higher in control soil than in contaminated soil (except at day 7), the difference being more pronounced at day 61 than at day 28. Feeding activity in controls was positively related to temperature for the 7 day (both in control and contaminated soil) and 28 day (only in control soil) exposures (one way ANOVA; Holm–Sidak method p < 0.001). For the longer exposure durations there were no apparent temperature relationship (Fig. 3a). The higher feeding activity in the control soil is in agreement with the total abundance of organisms (Fig. 3b) mainly during the first 28 days (growing phase).