Figure 2. Voluntary interaction with the handler immediately before and after mice were picked up by a shared tunnel or tail.

Percentage of test time interacting with the handler immediately before (b, solid bars) and after (a, hatched bars) the first, fifth and ninth handling session for C57 and ICR mice picked up by one of two different handling methods (mean ± s.e.m., n = 8 cages for each handling group and strain). Shared Tunnel Only and Tail mice were kept under the same housing conditions and neither had any prior experience of tunnels. P values indicate the effect of handling method (repeated measures ANOVAs, full analyses given in Table S1). There was a significant interaction between handling method and strain in session 1 (F_1,26 = 22.2, P<0.001) and session 5 (F_1,26 = 19.5, P<0.001) but not in session 9 (F_1,24 = 0.1, P = 0.74).