Animal's social grooming activities are services "exchanged" for specific types of cultural bonding, hence a form of barter.
"Social grooming between members of the same species. Grooming is a major social activity and a means by which animals who live in close proximity may bond, reinforce social structures and family links, and build companionship. Social grooming is also used as a means of conflict resolution, maternal behavior, and reconciliation in some species."
Animal's social grooming activities are services "exchanged" for specific types of cultural bonding, hence a form of barter.
"Social grooming between members of the same species. Grooming is a major social activity and a means by which animals who live in close proximity may bond, reinforce social structures and family links, and build companionship. Social grooming is also used as a means of conflict resolution, maternal behavior, and reconciliation in some species."