Filipino children play as they are doing caroling activities on the street near an airport, days before Christmas in Manila, Philippines, 20 December 2017. Filipinos celebrate the longest Christmas in the world which starts as early as September every year. (Photo by Francis R. Malasig/EPA/EFE)

Spot-billed pelican interact on the banks of an artificial lake in Colombo on September 28, 2021. (Photo by Ishara S. Kodikara/AFP Photo)

A woman walks protecting herself from rain after Hurricane Matthew in Les Anglais, Haiti, October 13, 2016. (Photo by Andres Martinez Casares/Reuters)

A seafood vendor moves a giant swordfish to his stall at a market in Qingdao, Shandong province, China, September 12, 2015. The 4.1-metre-long (13.5 feet) swordfish, weighed about 309.5 kilograms (682 lbs), was caught by local fishermen on Friday, local media reported. (Photo by Reuters/Stringer)

A woman carries a stone cross in a cemetery in the village of Copaciu, southern Romania, on May 2, 2013. As part of a Holy Week tradition, Romanians visit, on Maundy Thursday, the graves of their loved ones, light fires and share food with community members in memory of the departed. Orthodox worshipers celebrate Easter on May 5. (Photo by Andreea Alexandru/ Mediafax)

A mine detection rat is given banana as a reward after successfully identifying an inactive mine on July 2, 2015 in Siem Reap, Cambodia. The Cambodian Mine Action Center (CMAC) working with the Belgian NGO APOPO has recently begun testing the feasability of using large mine detection rats from Tanzania to help clear fields of mines and unexploded ordnance in one of the most bombed and mined countries in the world. (Photo by Taylor Weidman/Getty Images)

Duncan Fenton from the Society of William Wallace stands next to a 700-year-old letter believed to have been in the possession of William Wallace, which has returned to National Records of Scotland on January 12, 2012 in Edinburgh, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

Google has built its first self-driving car prototypes and hopes to test hundreds more models this summer. If all goes well, the company is planning a pilot program in California over the next few years.