[Intestinal flora and social relations in laboratory rats]

This paper deals with the quantitative study of the social interaction in dyads of laboratory rats. Two kinds of dyads of Rattus norvegicus were observed: one which had the conventional rat intestinal flora (S.S.C.u.p.) and the other a micro-flora (J.L.T.) derived from feral rats, each member of the dyad having the same sex. Contact-seeking and sniffing behaviour were more frequent and lasted longer in J.L.T. rats than in S.S.C.u.p.