Question about main effect and post hoc analyses


New Member
I have a group of animals that I'm running stats on. In one case, I have no main effect of treatment, but post-hoc analyses reveals significant differences between vehicle and treatment.

So, my question is, how is it that there is no treatment main effect, but post hoc is significant? What does that mean? Also, for clarity, I ran a one-way RM Anova with Dunnetts multiple comparisons.