A staff feeds one Siberian tiger cub of the quintuplets with milk at the China Hengdaohezi Feline Breeding Center in Linhai City, northeast China's Heilongjiang Province, April 24, 2018. A female Siberian tiger gave birth to quintuplets at the center and it has had over 20 offspring in total since its first delivery in 2011. (Xinhua/Zhang Chunxiang)