Relative frequency (mean ± SE) of allogrooming events per hive and observation day detected inside the nest in Varroa-free and Varroa-infested colonies depending on the position in the frame in relation to the hive entrance [lower and upper position near the entrance (LE and UE), lower and upper central position (LC and UC), lower and upper position far from the entrance (LF and UF)]. ns, P > 0.05; and *P < 0.05. From: