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.

Elephant fights off hyenas to save baby. “This is the incredible moment an elephant came to the rescue of one of its babies being attacked by a pack of hyenas. The elephant is seen charging at the hyenas to ward them off its offspring. The photos were captured by American photographer Jayesh Mehta, 47, in the Savuti region of the Chobe National Park in Botswana”. Photo: The elephant is seen charging at the hyenas to ward them off its offspring. (Photo by Jayesh Mehta/Caters News)

Joe Deedon, president of TAC ONE Consulting, demonstrates searching for a shooter in a middle school during an Active Shooter Response course offered by TAC ONE in Denver April 2, 2016. According to TAC ONE, the course, which is offered for the first time to concealed weapons permit carrying civilians, is designed at preparing people to effectively save lives prior to the arrival of law enforcement at an active shooter incident. (Photo by Rick Wilking/Reuters)

Daredevil Christopher Gillette writhes around with a huge alligator he has saved from death. He works at a Florida sanctuary that rescues the wild beasts if they stroll into neighbourhoods where residents can legally kill them. To raise cash for the centre at Homestead, staff put on shows to feed and wrestle the alligators. Photographer John Chapa, 41, and girlfriend Adriana Canargo, 30, took these shots. Photo: Assistant photographer Adriana Canargo dives with a wild alligator. (Photo by John Chapa/Barcroft Media)

A pet horse tethered on land known as “The Cracker” in Tipton that may be seized by bailiffs on October 10, 2011 in Dudley, England. Horse lovers in Tipton are battling the local council over the tradition of keeping their horses tethered on public land near their homes. Locals say tradition that has been in existence for generations and believe it stems from the age of the canal when many local men used their horses to tow canal barges along the industrial Black Country canals. After a spate of horses running free Sandwell Council are now enforcing the law and impounding tethered horses. Locals are planning their next protest with a horse drive to the council headquarters to try and save their traditions. (Photo by Christopher Furlong/Getty Images)

A picture made with a tilt-shift lens shows “Dwarf Empire” cast member 19-year-old Han Zhen Yan posing in her fairy costume backstage outside one of the fairy tale-like houses at the Dwarf Empire theme park outside Kunming, China's Yunnan province, 04 April 2013. The Dwarf Empire theme park opened in mid-2009, employing a number of dwarves to create the show. Depending on what type of job they do at the park, employees earn between 800-2,000 CNY (100-250 Euros) per month, most of which goes towards their savings as lodging is provided, and their living quarters are equipped with kitchens where they prepare their own meals. (Photo by Diego Azubel/EPA)

BERLIN, GERMANY - NOVEMBER 11: Sculptor Oleg Bessonov creates a rosette from clay at the Schlossbauhuette studio where a team of sculptors is creating decorative elements for the facade of the Berliner Schloss city palace on November 11, 2011 in Berlin, Germany. The Berliner Schloss was the residence of the Prussian Kaiser and was among the major architectural landmarks of Berlin until it was heavily damaged by Allied bombing in 1945. The communist authorities of East Berlin demolished the building in the 1950s, and today's Berlin government is pursuing an ambitious project to rebuild the palace according to a design by Italian architect Franco Stella, which will recreate the facade of the building but with a modern interior at a cost of approximately EUR 590 million. The Humboldt Forum, the foundation leading the project, has given the Schlossbauhuette sculptors the formidable task of recreating the hundreds of architectural elements that decorated the facade, and though some original pieces were saved, more often the sculptors have only old black and white photos as reference. (Photo by Sean Gallup/Getty Images)

A rat's head rests as it is constricted in an opening in the bottom of a garbage can in the Brooklyn borough of New York, U.S., October 18, 2016. The Brooklyn rat was saved on Tuesday after getting its head stuck in the dumpster while scavenging for food, according to the New York Daily News. As the rat was scurrying around the bottom of the trash can, it came across a few ventilation holes. The hungry creature poked his head into one of them, but to its dismay couldn't get back out,Reuters photographer Lucas Jackson told the Daily News. Jackson was able to take some adorable photos of the rat's unfortunate situation before it was rescued. (Photo by Lucas Jackson/Reuters)