Story highlights More than 3 tons of pangolin scales were seized by Shanghai customs officers

Pangolins are endangered, and it's illegal to import or export them in China

(CNN) The pangolin, a scaly anteater who sleeps by day and eats insects by night, is more popular than ever in China. But that very demand -- often wanted for illegal reasons, like the purchase of its meat or scales -- has driven the mammal toward extinction.

The illegal trade of pangolins hit a new milestone this month when Shanghai customs officials seized more than 3 tons of pangolin scales --the largest pangolin seizure in China's history, officials said. Three suspects were captured.

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On December 10, Shanghai customs officials inspected a container that arrived from Africa filled with large logs. When the shipment entered an X-ray machine, though, officials noticed items of an "uneven texture," which caught their attention.

When customs officers unpacked the container, they found the front part filled with different kinds of wood, and pangolin scales toward the back. A final inspection yielded 101 packets that weights a total of 3.4 tons.

Animal protection experts estimate each pangolin has about a half-pound of scales -- which leads them to believe that between 5,000 and 7,500 pangolins were killed for this shipment.

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