Two are giggling at something off camera, while their brother has a curious look on his face.
It is a bittersweet occasion. The boys are the Magaoa triplets, who are celebrating their first birthday.
It is also a different kind of anniversary - a year since their mother, New Zealand-born woman Chervonne Magaoa, died shortly after giving birth to them.
The 34-year-old's father, Bishop Hyran Smith, told the New Zealand Herald the past week had been one of celebration - but the loss was still felt.
"The boys are all taking steps now - almost completely walking, but not quite. They're getting a few steps out now if you put them in the middle of the room.
"We had their birthday on Saturday. On Friday, we had the unveiling [of the headstone] for my daughter.''
Chervonne, born in Hastings but raised in Hawaii, died on August 31 after suffering an amniotic fluid embolism.
The rare condition occurs when amniotic fluid - which surrounds a baby in the uterus during pregnancy - enters the mother's bloodstream.
People from around New Zealand, Hawaii and the United States rallied to help the whānau, including husband Martin Magaoa and the couple's then 6-year-old son Tanner, when the news broke.
A headstone for the boys' mother was unveiled on their actual birthday, while their colourful party was held the next day.
The headstone has a photo of a pregnant Chervonne, with the words: "To my children. If I had to choose between losing you and breathing, I would use my last breath to tell you I love you.''
Smith said his daughter had actually revealed what she was planning to do for her triplet sons' first birthday, during pregnancy.
"Chervonne had already talked with me and my other daughter about having a carnival for the babies' 1-year-old birthday. So we made it a reality.''
Up to 500 people turned out to the event, which featured face painting, balloon twisters and shaved ice.
"The triplets each had their own cake and we let them smash them,'' their grandfather said.
"It wasn't just for the triplets. It was for everyone - it was a thank you to the community."
Since the boys were born, volunteers - mothers and grandmothers from the family's church and local Māori and Pacific community - have come in each day to help look after them.
A log is filled out for each boy; showing when they eat, how much they weigh, when they sleep and other details.
With more than 100 volunteer nannies now signed up to help, Smith laughed that his grandsons were quite famous in the area.
"Because they've had so many nannies come and watch them, they go to anybody.
"You could walk in off the street and they'd go to you. They're not afraid of anyone.
"I said to my wife: 'When they grow up, they're gonna have all these random ladies come up to them and say: 'I used to change your diaper when you were a baby'!"
