Brad Pitt & Angelina Jolie: Their Family

They've munched on crickets in Cambodia and surfed the waves in Cancun, but for the six children of Brad Pitt and Angelina Jolie, life in the boisterous family is as much about everyday bonding as it is the big adventure.

"The children are always playing, jumping on each other and sharing fun moments," a source tells PEOPLE in this week's cover story. "They share a special bond."

Leading the pack: oldest son Maddox, 10, who "is almost like a teenager now, the way he understands things," says another source. "He's grown up very quickly."

But his younger siblings are rapidly growing up, too. Six-year-old Zahara and her 5-year-old sister Shiloh are especially close, while 7-year-old Pax "has become more independent in the past year," says an insider. And with twins Knox and Vivienne now 3 – they help pack their own suitcases! – the family is settling into a lower-key, if still decidedly adventurous, rhythm.