This distinction is made at least since 1995: https://pubmed.ncbi.nlm.nih.gov/13260820/ https://pubmed.ncbi.nlm.nih.gov/13260820/ - distinguishing between sex a

This distinction is made at least since 1995: https://pubmed.ncbi.nlm.nih.gov/13260820/ https://pubmed.ncbi.nlm.nih.gov/13260820/ - distinguishing between sex as physical/physiological characteristics and gender as psychological ones. I'd assume it's quite unlikely mice care about psychological characteristics of researchers, but it'd be an interesting piece of research to read :)