Decoding diversity: Are there patterns in the organization of grooming movements in domestic cats?

Grooming is crucial for mammalian health and hygiene, serving diverse functions such as parasite defense, removing dirt, and thermoregulation. Grooming is not purely reactive but integrated into daily routines and regulated endogenously. In rodents, it has been shown to follow a sequential structure with predictable patterns, often interpreted as reflecting pattern-generating neurological programs. In this study, we examined the temporal and spatial structure of self-grooming sequences in cats to test whether grooming in this species follows similarly predictable patterns. Grooming performance in 17 cats was recorded, and 40 sequences were analyzed to discern the allocation of grooming time to different body areas. Pattern analyses reveal the temporal order in which body areas were cleaned. Oral grooming occupies the largest portion of grooming time, whereas face washing and scratching were less frequent. High individual variation was found in the distribution of grooming time across body areas and in the spatiotemporal order of sequences, challenging the idea of strict patterns and grooming rules in cats. Instead, our analyses indicate that grooming is structured by probabilistic transitions between spatially adjacent body regions. We conclude that grooming sequences in cats are primarily determined by the spatial proximity of grooming targets and movement efficiency.