ABSTRACT.- Twin lambs establish a social attachment soon after birth, which implies that they prefer to interact with each other during the suckling period. However, the role of the mother's presence in maintaining the social attachment between twins has been scarcely studied. The aims of this study were to characterize the dynamics of the distance between twin lambs during lactation until three months after weaning, and to determine the impact of the mother in this regard. The study was performed with 11 East Friesian multiparous ewes, nine Finnish Landrace multiparous ewes, and their twin lambs under grazing conditions. © 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.