Abstract: A method is provided of determining a relationship between a first animal and a second animal, which method comprises the steps of: (i) generating a proximity profile comprising information in relation to the frequency and duration of incidences of proximity for a candidate first animal in relation to the one or more candidate second animals; and (ii) analysing the proximity profile to determine whether the interaction between the candidate first animal and any of the candidate second animals is indicative of a relationship between the animals. Also provided is a system for use in such a method.