Charlize Theron with son Jackson on May 8, 2012. Credit: AKM-GSI

Charlize Theron already had a couple of little ones at home before she brought home 9-day-old Jackson in March.

In a Thursday appearance on The Ellen DeGeneres Show, the Snow White and the Huntsman star, 36, opened up about expanding her brood--and how her rescue dogs responded to the newest addition to the family.

"Dogs tend to . . .it takes them a little bit to really fall madly in love with someone," Theron said of her two rescue pups, a terrier mutt and a pitbull. "They know their owner and they'll be friendly, but they won't fall madly in love with just a stranger instantly."

But when the actress brought home her son, it was a totally different story. "From the moment this baby came into our home, those two dogs have never been more in love," Theron revealed. "It's the most beautiful thing I've ever witnessed."

Her pitbull, Blue, in particular has been "really beyond," she shared. "The pit woke up with me for every feed, for every change. And whenever the baby would cry, the pit would start crying."

Added Theron, "People keep saying, 'You're a single mom.' I go, 'Actually, I'm not. I got two boys helping me out.'"

The Prometheus actress also opened up to DeGeneres about her roller-coaster two-year adoption process--tearing up as she recounted her story.

"My mom said the most beautiful thing. She said, 'You know, it took me nine months to fall in love with you while you were growing in my stomach, and it took you two years to fall in love with this little baby,'" Theron said. "It took two years of waiting, and then one day, it's finally there, and it feels exactly how it's supposed to feel. I don't know how to describe it. It just feels right."