hygienic standpoint, then the larger an animal, the more and more often it would be groomed by members of its group. However, we see instead that when group size increases, members ensure that they spend an appropriate amount of time grooming everyone. Hence, the fact that animals, particularly primates here, groom each other more frequently than necessary from a hygienic standpoint suggests that the social angle of allogrooming plays an equally, if not more, important role. Another point of evidence for the importance of the social aspect is that in comparison to how much and how a primate grooms itself (autogrooming), allogrooming involved longer periods of time and different techniques, some of which have connotations of being affectionate gestures. Reinforcing social structure and building relationships Creation and maintenance of social bonds One of the most critical functions of social grooming is to establish social networks and relationships. In many species, individuals form close social connections dubbed "friendships" due to long durations spent together doing activities. In primates especially, grooming is known to have major social significance and function in the formation and maintenance of these friendships. Studies performed on rhesus macaques showed that fMRI scans of the monkeys' brains lit up more significantly at the perirhinial cortex (associated with recognition and memory) and the temporal pole (associated with social and emotional processing/analysis) when the monkeys were shown pictures of their friends' faces as compared to less familiar faces. Hence, primates recognize familiar and well-liked individuals ('friends') and spend more time grooming them as compared to less favoured partners. In species with a more tolerant social style, such as Barbary macaques, it is seen that females choose their grooming mates based on whom they know better rather than on social rank. In addition to primates, animals such as deer, cows, horses, vole, mice, meerkats, coati, lions, birds, bats also form social bonds through grooming behaviour. Social grooming may also serve to establish and recognize mates or amorous partners. For example, in short-nosed fruit bats, the females initiate grooming with the males just before flight at dusk. The male and his close-knit female harem apply bodily secretions on each other, which could possibly allow them to recognize the female's reproductive status. The 2016 study by Kumar et al. chemically analyzed these secretions, revealing that they may be required in chemosensory mediated communication and mate choice. Similarly, in the less aggressive herb-field mice