SAN FRANCISCO (CBS SF) – Customs officials say they have thwarted a plan to sneak twenty live millipedes inside a box coming through the international mail facility at San Francisco International.

U.S. Customs and Border Protection agriculture specialists made the discovery inside a box marked “toy car model.”

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The large package from Germany had been x-rayed and agents noticed that it didn’t seem to contain a toy.

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“Customs and Border Protection officers and agriculture specialists routinely x-ray and inspect packages arriving from foreign locations for contraband and other prohibited items before they are permitted to enter the U.S.” said Brian J. Humphrey, CBP Director of Field Operations in San Francisco. “The agriculture specialists on duty were quick to notice the deception and took the necessary action.”

(U.S. Customs and Border Protection)

(U.S. Customs and Border Protection)

The foot-long millipedes were stashed inside a mesh bag contained inside a Styrofoam box full of dirt and paper. They were handed over to the U.S. Department of Agriculture because the sender did not have proper permits.

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Giant millipedes are most commonly found on the coast of central Africa and can live up to eight years in captivity, according to zoologist. Officials did not release the intended destination, and it’s not clear why someone in the states wanted them.