“…At a proximate level of explanation, establishment of preferential nipple use in the cat almost certainly depends, at least in part, on olfactory cues. Thus, in a study in progress (Hudson, Raihani, González, Arteaga, & Distel, 2008) we have found that kittens respond with nipple-search behavior and attachment when placed in contact with the ventrum of late pregnant or lactating females but not of mature, nonreproducing females (reviews in Bautista et al, 2008;Hudson, Rojas, Arteaga, Martínez-Gómez, & Distel, 2008 for a similar phenomenon in domestic rabbits). Furthermore, in agreement with the suggestion by Ewer (1961) and present observations of nipple constancy when mothers changed the side they lay on to nurse, that kittens use local olfactory cues rather than topographical features of the mother to identify their primary nipples, we have found that kittens do not preferentially attach to the equivalent of their primary nipple when tested on a female of similar lactational age to their mother (Hudson, Raihani, González, Arteaga, & Distel, 2008).…”