Galagos communicate by calling to each other and by marking their paths with urine. By following the scent of urine, they can land on exactly the same branch every time. Each species produces a unique set of loud calls that have different functions. One function is to identify individuals as members of a particular species across distances. Scientists can recognize all known galago species by their 'loud calls'. At the end of the night, group members use a special rallying call and gather to sleep in a nest of leaves, a group of branches, or a hole in a tree.