Canterbury Christ Church, Sussex - Mules outsmart mum and dad

Mules, hybrids of donkeys and horses, are smarter than either of their parent species, according to an intelligence test involving identification of the symbols on food buckets. Psychologist Britta Osthaus, of Canterbury Christ Church University, who carried out the study with Leanne Proops of the University of Sussex, said mules had been bred because they combined the best physical abilities of horses and donkeys. "The mules' performance was significantly better than that of either of the parent species and got faster over a period of time," Dr Osthaus said. Mules' bad reputation could stem from a lack of mental stimulation, leading to destructive behaviour, she said.