Object permanence is the notion that objects continue to exist even when they are out of observer´s sight. This ability is adaptive not only for free ranging animals who have to cope with a dangerous and highly changeable environment, allowing them to be aware of predators sneaking in their proximity or to keep track of conspecifics or food sources, even when out of sight. Farm animals, too, might profit from object permanence as the ability to follow the trajectory of hidden food or objects may lead to a higher ...