While bats use echolocation for orientation and foraging, recent studies have suggested that it functions for social communication as vocal signals can differ between groups, individuals, or sexes. However, previous studies have focused on bats using permanent roosts (e.g., caves) in large colonies, wherein echolocation calls would not always be important in communication because they can readily find roosts or group members. Here, we analyze social signatures of dark woolly bat, Kerivoula furva, which uses ephemeral roosts (furled plantain leaves) in small steady groups and moves roosts every day following foliation in summer. We hypothesized that echolocation call signatures of K. furva are different among groups and individuals for the potential use in group cohesion or individual recognition. Discriminant function analysis generally supported the hypothesis and showed 33.6% and 34.5% correct classification in group and individual signatures, respectively. However, our results were less apparent than other species signatures. Based on their unique ecology, we provide three mechanisms, the effect of group size, genetic variation, and ecological niche, to explain the role of echolocation communication in K. furva. Our study extends the communicative function in echolocation calls to understand the context-dependent social information.