“…As for any other behavior, animals can gather information from all sensory modalities in order to choose a potential mate. Without doubt (Beach, 1942 ), olfactory information is crucial for rodent mate choice (Coombes et al, 2018 ; Ferkin, 2018 ) and odors carry important information about sex (Johnston, 2003 ; Choleris et al, 2009 ; Hurst, 2009 ; Kondo and Hayashi, 2021 ), strain (Krackow and Matuschak, 1991 ; Laukaitis et al, 1997 ; Bímová et al, 2009 ; Zinck and Lima, 2013 ), social rank (Jemiolo et al, 1985 , 1991 ; Zhang et al, 2021 ), sexual receptivity (Novotny et al, 1990 ; Dulac and Torello, 2003 ), fitness (DeFries and McClearn, 1970 ; Oakeshott, 1974 ; Gill and Rissman, 1997 ; Temple et al, 2002 ), and health status (Kavaliers and Colwell, 1993 ; Zala et al, 2004 ; Kavaliers and Choleris, 2017 ) of conspecifics. Indeed, several studies describe a prominent role for pheromones during the initial sexual approach in rats (Carr, 1974 ; Kumar et al, 2014 ; Zhang et al, 2021 ) and mice (Roberts et al, 2010 , 2014 ; Haga-Yamanaka et al, 2014 ; Demir et al, 2020 ).…”