(A) Representative images of spontaneous void assay testing in adult virgin C57Bl/6J male mice singly or group housed from time of weaning to 6 weeks of age. (B) Quantification of mouse mass, spot number, total urine area, spot size (diameter), primary void area, percent area in primary void, corners and center. Results are mean±SE, n=9 single, n=19 (5 cages) group. (C) Representative images of spontaneous void assay testing in adult virgin C57Bl/6J male mice. Mice group housed from weaning to 8 weeks of age were void tested, separated into single housing for one week and void tested again, then paired with a multiparous female for one week followed by a void assay. (D) Quantification of urine area. (E) Quantification of urine area relative to mouse body mass. Results are mean±SE, n=6. Asterisk indicates significant differences p≤0.05.