Zoe Saldana's twins are like a "museum subject".

Zoe said: "It's like we wake up to go to a children's museum, and the kids are the subjects. That's all we do, is just observe them.

"They let us know that they are identical. They do a lot of physical things that kind of freak us out!"

But one thing the boys haven't yet got to grips with is the fact they have different names.

Zoe told E! News: "There's no Bowie. They call each other Cy! We're like, 'You're Cy, and that's Bowie,' and they're like, 'Cy?' "

The 38-year-old actress and her artist husband, 37, feel reassured by the bond between the twins as they can always rely on one another for comfort.

She said: "They have a great deal of empathy for each other. That's something my husband and I are seeing and it makes us so happy, because that thoughtfulness of if they hear the other cry...or if the other one leaves the vicinity that one is in, immediately it's like they perk up, and they're like, 'Cy?' and they walk and they have to find each other.

"Then once they find each other, you think they're gonna hug, they're gonna kiss - no. They find each other and they just cross [and keep walking], and sit on opposite sides of the room, but check each other out."

Zoe recently admitted she hates changing her sons' diapers and always tries to dodge the task.

She said: "Everybody told me, 'Oh, don't worry, I know you hate changing diapers, but when you have your own kid....'Well, guess what? I had my own kids, and I will do whatever I need to do to not change a dirty diaper.

"There is s**t on the boy; there is s**t on me; there is s**t in my hair. And I'm like, how did this happen?"