Since 2001, law has required pig farmers in the European Union to provide some form of entertainment to their livestock as a way of keeping them in good emotional health[!!! -ed.], which in turn helps curb aggression and anxiety. Often, toys and other materials are placed inside the sties for animals to interact with, but perhaps unsurprisingly, some farmers have found it quite difficult to turn their pigpens into playpens.via MetaFilter.
With that in mind, designers from Utrecht School of the Arts and Wageningen University in the Netherlands ventured to create new ways to make swine swoon -- resulting in a project called Playing with Pigs. But with a shortage of literature on entertaining pigs, developers soon found themselves experts in the field.