Dogs could in theory recognize funny business by paying attention to the number of treats — or the treats’ “numerosity,” as researchers often call a quantity recognized nonverbally. Nonhuman animals don’t have human language for counting, so researchers studying behavior talk about an “approximate number system” that allows for good-enough estimates of quantities with no real counting. Individual neurons in parts of a monkey brain have their own preferred number and respond most strongly to it and less so to neighboring numbers.