Bands are made up primarily of closely related individuals, although many bands also contain a few unrelated members. New bands may form by fission or fusion of existing bands. Migration of individuals between bands also occurs. Some males do associate with bands, perhaps to gain from the social grooming that removes ectoparasites, or for protection from potential predators and from other adult males. Coatis have a wide range of social behavior, including cooperative grooming, nursing, vigilance, and aggressive anti-predator behavior.
Bands are usually slightly agonistic to other bands when they meet.
However, peaceful interactions also occur, and are occasionally characterized be inter-group grooming sessions. Adult males that approach bands are generally aggressively chased away by one or several band members, including juveniles and subadults. Females often groom one another in an excited manner following such chases. During the breeding season males are submissive to females and immatures, and occasionally groom them. Bands often break into subgroups for several hours or occasionally 1-2 days.