Mexican authorities searching a man with a bulge under his shirt at the airport in the nation's capital found 18 monkeys hidden beneath his clothes. Mexico's Pubic Safety Department said investigators grew suspicious after Roberto Sol Cabrera Zavaleta, 38, became markedly nervous when asked what he was transporting. In a statement, the department said two of the tiny titi monkeys he was carrying in a belt were dead and 16 of them survived the journey from Lima, Peru. Cabrera has been detained as authorities continue their investigation. In an interview with authorities released by police, Cabrera said he first carried the monkeys in his suitcase, but then hid the animals in his clothes so they would not be harmed by X-ray machines at the airport. He described the animals as pets and told authorities he had purchased them for 30 dollars. Police said titi monkeys are protected endangered species requiring a permit for possession.