cows controlled by the callers around their necks. irate cows controlled by the callers around their necks. cows controlled by the callers around their necks. we have a solar anel on around their necks. we have a solar panel on the around their necks. we have a solar panel on the back around their necks. we have a solar panel on the back here around their necks. we have a solar panel on the back here which - around their necks. we have a solar. panel on the back here which charges the battery. they are lightweight and flexible so cows can move around easily and there is a gps locator on the top so we can see exactly what the top so we can see exactly what the cows are at any one time and that links to a virtual fence which is wherever we wanted to be, really. the national trust can map out an area that they want raised on a mobile phone app. if the car reaches the invisible boundary it several music alerts and if it doesn t turn back, trying to cross the virtual fence, the car g