The San Francisco Zoo's polar bears had a birthday surprise today—the zoo brought in 10 tons of man-made snow to celebrated Pike's 30th birthday and Ulu's 32nd birthday. Plus there were other treats, like a fish popsicle in the shape of a teddy bear!

According to the zoo, polar bears' actual favorite food is seals: "The bears swim underwater to the edges of ice floes, leaping out to catch seals sunning themselves. Polar bears can leap seven to eight feet out of the water from a swimming start. The bears will also inch across the ice incredibly slowly to sneak up on seals before they can slide into the water. Polar bears are the most carnivorous of all bears. Besides seals, they eat small mammals, caribou, fish and carrion, and in the summer, they eat berries and vegetation. At the Zoo, the polar bears are fed meat, fish, fruit and vegetables."

Here's video from this 2010 Snow Day: