There is definitely something in the water at Taronga Zoo in Sydney, with the birth of the second litter of meerkat pups this year.

The two yet-to-be-named pups were born to parents Nairobi and Maputo, who also welcomed pups Lwazi and Serati in January.

Although the new pups were born on August 18, they have just started venturing outside their nest box.

The new additions with their dad Maputo. ( Supplied: Paul Fahy )

"They were eager to investigate their new surroundings. These pups are more confident and adventurous than the previous litter and I think that's because they have mum, dad and two siblings to support and protect them," zookeeper Courtney Mahony said.

"They are fantastic and attentive parents, but it's also been wonderful to watch big sister Serati play a role in caring for the pups."

The keepers said Serati was always grooming, babysitting and checking up on the pups.

"It's incredible to see such a young meerkat stepping up and taking on that responsibility," Ms Mahoney said.

The sex of the pups will be confirmed at their first veterinary examination next month, but keepers suspect they are both female.

They are growing quickly and despite only weighing a few grams when they were born, they now both tip the scales at more than 150 grams and have begun to try solids including mealworms and vegetables.

Keen visitors will be able to see the little ones for short periods each day as the pups are slowly introduced to the outside world.