It turns out that even dogs can understand the simple essence of commodity-money relations, as demonstrated by a dog named Negro who lives in the territory of the Technical College of Colombia. The dog repeatedly observed how students bought different products at the local store, including cookies for it, giving something in return. The observant dog decided to follow their example, but instead of money he brought a leaf of a tree. The saleswoman could not resist such an act and gave Negro his favorite cookies. Since then, the dog regularly visits the store, bringing the leaves, in return for which he receives a treat.