Five tiny Pallas's cats, known for their permanently grumpy-looking faces, are now delighting visitors at Kobe Animal Kingdom in Japan. The four male and one female kittens were born at the zoo in May and went on public display last Thursday, marking a rare success for one of the world's oldest and most sensitive cat species.

Weighing just 150 grams—about as heavy as a small orange—when they were born in May, the kittens have grown to over one kilogram and are already starting to eat solid foods like chicken and horse meat. Zoo officials say the young cats are thriving, playing and sleeping soundly in their enclosure.

Pallas's cats are considered the oldest living feline species still in existence today. These grumpy-faced creatures are native to the dry, rocky landscapes of Central Asia, from Iran to northern China and across Mongolia. Their distinctive scowling expression comes from their unique facial structure and thick fur that helps them survive in harsh environments.

The species is rarely displayed at zoos around the world because the animals are particularly sensitive to infections. The Kobe zoo carefully monitored the kittens through their early weeks before deciding they were healthy enough to meet the public.

"We hope people will come and see how healthy they are, playing wholeheartedly and sleeping soundly like kids," the zoo said in a statement.

The successful display of these five kittens represents a small but meaningful achievement for the species, which faces pressures in the wild from habitat loss and hunting. Seeing young Pallas's cats growing up strong and curious offers a glimpse of hope for their future—both in zoos and in their natural Central Asian homes.

Visitors to Kobe Animal Kingdom can now see the grumpy-faced kittens for themselves, watching them play and explore just like any young cats would—minus the friendly temperament their domestic cousins are known for.