Two Himalayan black bears at Sapporo Maruyama Zoo in Hokkaido, the northern main island of Japan, are gaining a reputation for relaxing in an empty water tub.

The female bears Minami, 22 and Tomo, 19, both 1.6 meter tall, love the stainless steel tub, which is around 1 meter long, 50 cm wide and 30 cm deep. They began taking turns sitting in the tub from late last year after zoo workers emptied it of water.

"They look almost like humans lazing about at home," a zoo official said.

Showing no trace of self-consciousness, the bears yawn and scratch their heads and legs. "How lazy," laughed one visitor, among many who have been lapping up the sight of them.

Ayako Nagano, who works at the zoo, said the bears may find the temperature inside the tub comfortable and like how they fit into it.

Although staff fill the tub with hay, the bears remove it so they can climb inside, according to the zoo.

The Himalayan black bear is classified as the same species as the Asian black bear. They make their habitat in Nepal and China and are known to be good at climbing trees.

But Minami and Tomo rarely exhibit any inclination to show off their climbing prowess, according to the zoo, preferring instead to laze around in their tub.