At the laboratory in Dummerstorf, Germany, the researchers put the cattle in the special area, waited until they urinated and then gave them a treat: a sweet liquid of mostly molasses.

在德国杜梅尔斯托尔夫的实验室，研究人员把牛放在特定的区域，等到它们排尿后再给它们一种食物：一种主要由糖蜜制成的甜的液体。