Passengers ride an articulated bus known as a “bendy bus” on December 9, 2011 in London, England. The last remaining bendy bus will go out of service at midnight. London Mayor Boris Johnson called them cumbersome and pledged to remove them. 500 new buses are being introduced as replacements. (Photo by Peter Macdiarmid/Getty Images)

These photographs of hundreds of ducks following their leader down a river are truly mesmerizing. Rafeur Rahman of Bangladesh climbed a high bridge and saw hundreds of ducks apparently playing a game of follow the leader. More than 500 ducks live on the river, where the mosses and snails provide the perfect habitat. Here: Ducks in the river Baral in Bangladesh. (Photo by Rafeur Rahman/Caters News Agency)

Jaison Vargas, crocodile tour guide, takes a picture of an American crocodile (Crocodylus acutus) during a tour at the Tarcoles river, in Tarcoles, Garabito municipality, Costa Rica, on March 31, 2022. Crocodile tours in the estuary of the Tarcoles River are a popular attraction for visitors to Costa Rica's Pacific coast, as the area gets back on its feet after being shaken by the pandemic. The river is home to nearly 500 species of birds and some 2,000 American crocodiles, many of which have been named after famous people. (Photo by Luis Acosta/AFP Photo)

Wanwisa, a Lao Yi Lai Heng Chinese opera performer waits backstage at the Plub Plachai temple on January 25, 2012 in Bangkok, Thailand. The traditional Chinese art form involving music, singing, martial arts and acting has a history of more than 500 years. There are about 30 members working with the group doing specials shows all week to celebrate the Chinese New year. The Chinese opera is popular in many parts of China, Malaysia, Singapore, Thailand and Macau. (Photo by Paula Bronstein/Getty Images)

Afghan children wait as their mothers receive treatment at a USAID-funded health center on September 7, 2011 in Farza, Afghanistan. Almost 10 years after the 9/11 attacks and the U.S. invasion of Afghanistan, the U.S. government funds some of 500 Afghan health facilities nationwide, most run by non-governmental organizations contracted by the Afghan Ministry of Public Health. (Photo by John Moore/Getty Images)

A Chinese tourist wears protective gloves as she holds a baby Siberian tiger as they pose for pictures at the Heilongjiang Siberian Tiger Park on August 16, 2017 in Harbin, northern China. The center is one of two Siberian tiger parks in the Chinese province of Heilongjiang, about 500 kilometers (300 miles) from the border with Russia. It is considered the world's largest for breeding the Siberian, or Amur, tiger which is listed as endangered by the World Wildlife Federation. (Photo by Kevin Frayer/Getty Images)

This Hawaiian cat sanctuary has created an “island paradise” for the state’s stray cats. Although most people would take a trip to one of the Hawaiian Islands’ many heavenly sights, Andrew Marttila, 32, and his partner, Hannah Shaw, 30, wanted to visit something more unusual. They decided to take a trip to the Lanai Cat Sanctuary, which is currently home to more than 500 felines. Here: Kitten Lady, 30, is surrounded by rescued cats at the the Lanai Cat Sanctuary in Hawaii. (Photo by Andrew Marttila/Caters News Agency)

A firefighter recovers after climbing the 1800 steps of the Costanera Centre Tower as part of the “Race for Life” aimed at encouraging organ donation in Chile, in Santiago, on October 16, 2016. More than 500 volunteer firefighters are expected to climb the 1800 steps of the tallest building in South America to promote and encourage organ donation in the country. (Photo by Claudio Reyes/AFP Photo)