We describe novel aspects of the social organisation of the Pyrenean desman, Galemys pyrenaicus, by studying home range and shelter use behaviour in a local population. A total of 45 individuals were trapped of which 20 provided informative radiotracking data. In contrast to the currently accepted hypothesis [Stone RD. The social organization of the Pyrenean desman (Galemys pyrenaicus) as revealed by radiotelemetry. J Zool 212:117–129; 1987b; Stone RD, Gorman ML. Social organization of the European mole (Talpa europaea) and the Pyrenean desman (Galemys pyrenaicus). Mammal Rev 15 (1):35–42; 1985] individuals were not strictly territorial. Notably, there was no aggression between conspecifics, with simultaneous use of resting sites (shelters used for more than one hour). Resting sites were not permanent or exclusive for any individual. Individuals shared resting sites simultaneously, regardless of sex or age. Our observations recall for a new evaluation of the social structure and organisation of this species based on the new evidence that reveals higher frequency of social interactions than previously described. Resting sites may play an important role in the social organisation of the species, for instance by allowing direct and indirect communicative interactions among neighbouring individuals. This finding is of significance for the management (e.g. census and population monitoring) and conservation (e.g. habitat suitability to allow social interactions) of this endemic and seriously threatened unique mammal.