[Images via Zooborns.]

National Zoo Staff have determined that the genetically valuable litter of two clouded leopard cubs born at the Smithsonian Conservation Biology Institute in Front Royal, Va. Feb. 14 (Valentine's Day) are both male. The cubs are now eating up to 88 grams of feline diet, two times per day, in addition to formula. The cubs are growing at a steady and healthy rate-the larger cub weighs 4 pounds and 9 ounces and the smaller cub weighs 4 pounds and 7 ounces. In addition, the cubs now ‘chuff,' which can be described as a puffing sound and is considered a sign of recognition. They are very playful-rolling around and chasing each other-after each feeding.

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