Good boy!

For the last five years or so, the campus of Colombia’s Diversified Technical Education Institute of Monterrey Casanare has been home to a sweet black dog named Negro. There, he serves as a guardian of sorts, keeping watch over things as students go about their studies.

Early on in Negro’s tenure at the school, he came to be aware of the little store on campus where students gather to buy things on their breaks; sometimes they’d buy him cookies sold there.

This, evidently, is where the dog first learned about commerce — and decided to try it out himself.

“He would go to the store and watch the children give money and receive something in exchange,” teacher Angela Garcia Bernal told The Dodo. “Then one day, spontaneous, he appeared with a leaf in his mouth, wagging his tail and letting it be known that he wanted a cookie.”

Read more via thedodo.com.