BANGLADESH-DHAKA-WORLD ANIMAL DAY

BANGLADESH-DHAKA-WORLD ANIMAL DAY

(221004) -- DHAKA, Oct. 4, 2022 (Xinhua) -- A zookeeper feeds hippopotamuses at the Bangladesh National Zoo in Dhaka, Bangladesh, on Oct. 4, 2022, the World Animal Day. (Xinhua)

Hippopotamus (Hippopotamus amphibius), hippo

Hippopotamus (Hippopotamus amphibius), hippo

Hippo Hippopotamus (Hippopotamus amphibius) cub is swimming in enclosure at the zoo Safari Park Dvur Kralove in Dvur Kralove nad Labem, Czech Republic, August 12, 2020. (CTK Photo/David Tanecek)

Hippopotamus (Hippopotamus amphibius), hippo

Hippopotamus (Hippopotamus amphibius), hippo

Hippo Hippopotamus (Hippopotamus amphibius) cub is swimming in enclosure at the zoo Safari Park Dvur Kralove in Dvur Kralove nad Labem, Czech Republic, August 12, 2020. (CTK Photo/David Tanecek)

Hippopotamus (Hippopotamus amphibius), hippo

Hippopotamus (Hippopotamus amphibius), hippo

Hippo Hippopotamus (Hippopotamus amphibius) cub is swimming in enclosure at the zoo Safari Park Dvur Kralove in Dvur Kralove nad Labem, Czech Republic, August 12, 2020. (CTK Photo/David Tanecek)

Hippopotamus (Hippopotamus amphibius), hippo

Hippopotamus (Hippopotamus amphibius), hippo

Hippo Hippopotamus (Hippopotamus amphibius) cub is swimming in enclosure at the zoo Safari Park Dvur Kralove in Dvur Kralove nad Labem, Czech Republic, August 12, 2020. (CTK Photo/David Tanecek)

Hippopotamus (Hippopotamus amphibius), hippo

Hippopotamus (Hippopotamus amphibius), hippo

Hippo Hippopotamus (Hippopotamus amphibius) cub is swimming in enclosure at the zoo Safari Park Dvur Kralove in Dvur Kralove nad Labem, Czech Republic, August 12, 2020. (CTK Photo/David Tanecek)

Night viewing at northern Japan zoo

Night viewing at northern Japan zoo

People watch hippopotamuses swim at Asahiyama Zoo in Asahikawa in Hokkaido, northern Japan, on the evening of Aug. 10, 2020, as the zoo extends its opening hours until 9 p.m. through Aug. 16 for visitors to observe animals in a nocturnal setting.