Two rare Sumatran tiger cubs were born this week at the National Zoo in the US capital, in what zookeepers described Thursday as a conservation victory for the critically endangered cats.
The births late Monday were a first for the tiger mom, Damai, who mated with the zoo's 12-year-old male Kavi.
The babies' eyes are not yet open, but they are nursing and crawling all over their mother, "as if her body is a jungle gym," the zoo said in a statement.
A webcam on the National Zoo's site showed black and white images of the cubs lounging and rolling in a darkened den with their mom on Thursday morning.
A zoo spokeswoman told AFP that no humans have come near the cubs yet, and they have no plans to for a couple of weeks.
"Not only are our two new Sumatran tiger cubs the cutest cubs in town but they are also a huge conservation success," the zoo statment said.
"With fewer than 500 Sumatran tigers in the wild, the birth of these cubs makes a stride in the direction towards saving this critically endangered species."
The only place in the world where these tigers are found in the wild is on the Indonesian island of Sumatra, where poaching and deforestation are major threats to the species' survival, according to the World Wildlife Fund.
Explore further: Research shows impact of BMR on brain size in fish