One‐day‐old spiny mouse pups responded preferentially to bedding soiled by lactating conspecifies fed the same diet as their mothers. Following this test, pups were fostered onto different‐diet females. When retested at 84–96 hr of age, no preferences were shown for bedding soiled by a female fed the biological mother's diet vs bedding of a female fed the different diet. When tested again at 120–132 hr of age, however, the pups preferred the bedding associated with their foster mother's diet. In a 2nd experiment, recently parturient females retrieved 1‐day‐old pups born of same‐diet females faster than pups born to novel‐diet females. These results indicate that pup preferences for chemical cues produced by lactating conspecifics can be altered by sufficient exposure to a 2nd female maintained on a different diet and that neonatal chemical cues, like maternal chemical stimuli, are diet‐dependent.