Authorities searching a man with a bulge under his shirt at Mexico City’s airport found 18 monkeys hidden beneath his clothes, according to CNN.

Investigators grew suspicious after Roberto Sol Cabrera Zavaleta, 38, became “markedly nervous” when asked what he was transporting, Mexico’s Pubic Safety Department said.

Zavaleta transported the monkeys from Lima, Peru. Two of the sixteen monkeys were dead. Cabrera has been detained as authorities continue their investigation, the statement said.

Zavaleta told police he originally carried the monkeys in his suitcase, but then hid the monkeys in his clothes so they wouldn’t be harmed by the airport’s x-ray machines (good thinking, hombre!) Unfortunately for him, the titi monkey is a protected endangered specie that requires a permit for possession (he claimed they were his pets and he purchased them for $30).