Some 525,000 American youngsters are living in foster homes, with families that are not their own. Government social workers have taken them - temporarily, and sometimes permanently - away from parents who are absent, abusive or incapable of caring for them. Experts say these kids are often so traumatized by what they have gone through with their own parents that they usually have many special needs.

Kathy Harrison and her husband, Bruce, have spent a lifetime raising children.

"We raised, altogether, about 120 kids," she says. "I should say obviously not at the same time. Kids can come to us for two days and they can be with us for two years. We have adopted four children. We already had three biological sons, when we started this journey."

That journey began almost 20 years ago. At the time, Harrison was a pre-school teacher, and a troubled 5-year-old girl came to her class. She was living with a foster family that wasn't able to meet her needs. When Harrison learned that the little girl was about to be sent to a psychiatric hospital, she felt she had to do something.

"My husband and I agreed to take her," she says. "I was familiar with her and I didn't think she belonged in a psychiatric hospital. Once we said we would take her, the social worker called that afternoon and said, 'By the way, did we mention that she has a sister?' I thought, 'Oh Dear, no one had mentioned that.' So we were parents of 3 at 8 o'clock in the morning, by 5 o'clock at night we were parents of five."

To become foster parents, the Harrisons had to be approved and get a license from the local government.

"Once we had that license in hand, and a big old house with empty bedrooms, the phone started to ring," she says. "I was moved by the plight of individual kids and when I heard their histories, I found it very impossible to say no."

With more children coming into their lives, Harrison says she decided to quit her job and stay at home to be better prepared to take care of them. "What I was not prepared for was how easy it was to fall in love with someone else's children, to have them feel as though they belong to me," she says.

The Harrison home was open to kids regardless of their ethnic, cultural or religious backgrounds. Kathy Harrison says that was challenging, because she had to learn and respect what mattered to each child. "One of the funny things that happened with my daughters is they just desperately missed their mother's cooking," she says. "They missed their Hispanic food and it was a nice way for me to connect with their birth mother because I was able to say to her at a visit, 'Annie, the kids really miss your 'platanos,' and I have no idea how to make it. Could you write down the recipe for me?' She did that. It was a way to connect and say, 'I respect not just your culture and identity but I respect your history.'"

What was more challenging, though, was meeting the children's emotional needs. Harrison says the kids needed to know that adults around them were trustworthy? that if they fall, someone will pick them up.

"So, even if a child comes to me and they are ten years old, if they haven't had that beginning stage, from birth to two years, you need to give that to them," she says. "They have to have it at some point in their life. So a lot of times kids come to me and people will say, 'you baby them!' I have to baby them because they never got a chance to be a baby. So, I do have to sort of hold them in my lap and meet their needs in a way you wouldn't meet the needs of a typical 10-year-old. Once they get this sense of security -- that I am, in fact, dependable -- they can move on to the next stage, they can move on to some more independence."

Inspired by her experience mothering foster children, Kathy Harrison has written two books, Another Place at the Table and One Small Boat. In both, she highlights the importance of understanding how those kids feel. "These foster kids have been 'hit by a bus,' experienced great trauma," she says. "They have lost everything anchors them to their sense of self. Losing their parents -- no matter how hard those parents were to live with -- is a huge life loss for kids."

That's where psychotherapy comes in according to psychologist Toni Vaughn Heineman,founder the Children's Psychotherapy Project, a nationwide program that offers free counseling to children in foster care. "It's very important that the therapist be able to work with the child and help the child master those losses and be able to form different kinds of relationships, including forming a healthy relationship with the foster parents," Heineman says.

"Our therapists, for example, work with both the child and the foster parents to strengthen that relationship," the psychologist says. "We know we are there maybe for one or two hours a week but the foster parent and the foster child are together all the time and we want to keep them together because every time a child loses a foster parent that just exacerbates all of those feelings of worthlessness, anxiety and depression that the child already brings to the family."

The entire Harrison family - parents, biological kids, adopted kids, and foster children - has gone through long-term psychotherapy. Kathy Harrison says that's one reason their experience has been so successful and rewarding. Most of her foster kids are now adults and helping other foster children. And the Harrisons still welcome foster kids into their home. Kathy Harrison says - after two decades of a full house - she feels really lonely when there aren't any children around.