Using a tiny high-resolution camera, zoo keeper Theo Kruse filmed two little Sri Lankan Leopard cubs playing and nursing from their mother in the family’s private maternity den at Burgers’ Zoo in The Netherlands.

The footage shows the two-month-old cubs, a male and a female, climbing on their mother and jostling for a prime nursing spot on mom’s belly.  The family has access to a spacious outdoor habitat but still spends a great deal of time in the cozy maternity den.

Photo Credit: Royal Burgers' Zoo

The cubs’ first veterinary exam, which was covered last month on ZooBorns, showed that the cubs are healthy and strong.

Sri Lankan Leopards are one of nine Leopard subspecies and live only on the island of Sri Lanka. With fewer than 1,000 of these Cats remaining in the wild, Sri Lankan Leopards are classified as Endangered by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.

Burgers’ Zoo has had great success breeding these rare Leopards and participates in the European Endangered Species Programme (EEP) of EAZA zoos (European Association of Zoos and Aquaria). Both parents are genetically valuable to the breeding program because they represent a new bloodline. This helps to keep the European zoo population as genetically diversified as possible.

See more photos of the cubs below.