Goyo, an eight-month-old mini pig, plays with a dog in Mexico City, December 21, 2015. Mini pigs can grow to about 30 kg (66.1 lbs) in weight and about 35 cm (1.1 ft) in height, according to the company Mini Pigs Mexico. The company says that the mini pigs' popularity as pets is growing and around 300 are sold every year in Mexico, with prices ranging from $350 to $1,600. (Photo by Edgard Garrido/Reuters)

Nepalese Mahuts with their elephant participate in elephant picnic as a part of the12th Chitawan Elephant Festival at Sauhara, Chitawan, some 154 kilometer from the capital of Kathmandu, Nepal, 28 December 2015. More than 80 elephant with their Mahuts joined the elephant picnic. The five-day festival began on 26 December to spread awareness about wildlife and promote tourism. (Photo by Hemanta Shrestha/EPA)

Members of the Jordanian police women's team attend the 7th Annual Warrior Competition at the King Abdullah Special Operations Training Center in Amman April 22, 2015. Thirty-eight teams from 18 countries are participating in the competition to test their military skills. (Photo by Muhammad Hamed/Reuters)

Francisca Gomez stands at an entrance to her home, a cave where she has been living for the past 50 years, in the mountains on the outskirts of Chusmuy, Honduras April 21, 2015. The 75-year old widow receives help from neighbors and friends and she makes a little money by selling wood she collects, according to a local newspaper. (Photo by Jorge Cabrera/Reuters)

Indian Muslim devotees travel in an auto rickshaw during the Urs festival in Ajmer, India, Thursday, April 23, 2015. Thousands of devotees from different parts of India travel to the shrine of Sufi saint Khwaja Moinuddin Chisht for the annual festival marking the saint's death anniversary. (Photo by Deepak Sharma/AP Photo)

In this March 18, 2015 photo, a boy rides a mechanical bull for children at the Texcoco Fair on the outskirts of Mexico City. In Mexico, these types of fairs date back to Spanish colonial times, and in some smaller communities they are organized around the feast days of Roman Catholic saints. (Photo by Eduardo Verdugo/AP Photo)

A firefighter uses a saw to open a metal gate while fighting a fire in a convenience store and residence during clashes after the funeral of Freddie Gray in Baltimore, Maryland in the early morning hours of April 28, 2015. (Photo by Eric Thayer/Reuters)

A Felix Airways plane is seen after it was destroyed by an airstrike at the international airport of Yemen's capital Sanaa, April 29, 2015. Jets from a Saudi-led alliance destroyed the runway of Yemen's Sanaa airport on Tuesday to prevent an Iranian plane from landing there, Saudi Arabia said, as fighting across the country killed at least 30 people. Airport officials said the strikes set a civilian aircraft operated by Yemeni Felix Airways ablaze. (Photo by Khaled Abdullah/Reuters)