Adding in female mice (who go through estrus cycles) is probably going to mess up your results and make them even harder to interpret. The article and its link

Adding in female mice (who go through estrus cycles) is probably going to mess up your results and make them even harder to interpret. The article and its linked sources address this point, citing two meta-analyses regarding mice and rats in neuroscience: https://www.ncbi.nlm.nih.gov/pubmed/24456941 https://www.ncbi.nlm.nih.gov/pubmed/24456941 "The underrepresentation of female mice in neuroscience and biomedical research is based on the assumption that females are intrinsically more variable than males and must be tested at each of four stages of the estrous cycle to generate reliable data. Neither belief is empirically based. [...] Utilization of female mice in neuroscience research does not require monitoring of the estrous cycle." https://www.ncbi.nlm.nih.gov/pubmed/27468347 https://www.ncbi.nlm.nih.gov/pubmed/27468347 "Across all traits, there were no sex differences in trait variability, as indicated by the CV, and there were no sex differences in any of the four neuroscience categories, even in instances in which mean values for males and females were significantly different. Female rats were not more variable at any stage of the estrous cycle than male rats."