London Zoo weigh-in

How do you weigh an ant? What does it take to size up a giraffe? The London Zoo weighs all 14,000 of its animals each August, from tiny insects to its largest mammals. Zookeepers have just completed their annual task. The World’s Marco Werman speaks with Jessica Fryer, the lead keeper for penguins and flying birds at the London Zoo, about how the animals were weighed, and why it’s important.