where n is the number of animals, i the index and xi is the number of ticks on the i-th animal.
Significance of differences was assessed between the log-counts of the live ticks of each treated group in comparison with the log-counts of the respective untreated control group for each assessment time point. The treated and control groups were compared using a linear mixed model that includes treatment group as a fixed effect and block as a random effect. The two-sided level of significance for the F-tests of the model effects was set to α = 0.05.