How do you deal with Biological Parents?
Depending on how open is your adoption. In our case our adoption is pretty open, Bio Mom (and bio Family) sometimes stop by and visit when they are in town. Thank God is not all together LOL. Our relationship is cordial, thankful in both ways, and respectful. That gave my daughter a feeling of emotional balance, she knows who is everybody. We share pictures with Bio Mom, and when health issues arrose she is notify too. The reason for this is in case there is something in the genes that I am not aware of, so the doctors don't loose time guessing what can it be.
Set boundaries, be hones & be kind. Always follow through, it's important for the children to understand and watch this lesson as you try to teach them.