Monkeys ‘learn to eat soil to cope with junk food’ BBCGibraltar macaques are self-medicating with dirt to help them digest human junk food Scientific AmericanGibraltar’s monkeys find a clever way to avoid a junk food bellyache YahooGibraltar’s monkeys eat mud ‘to avoid upset stomachs from tourist junk food’ The GuardianMonkeys have found a bizarre natural supplement to counteract human junk food BBC Science Focus Magazine