When you go through foster parent training you are made well aware of the challenges that many of the children in state care face. What they don't tell you is that you may face challenges of your own if dealing with the biological parents.
Many of these parents can be angry that the state has found them unfit for one reason or another and may direct this anger at you as the person caring for their child. Most feel that they have done nothing wrong and can't see why they do not have custody of their offspring. Thus, they will find a number of reasons to complain about the care you are giving their child. As a foster parent, you should be prepared for these potential pitfalls.
It goes without saying that many foster parents bring a child, or children into their home and treat them like family. They are treated no different than any of the legal children of the foster parents. As a result of this, a lot of kids, especially the young ones, may call their foster parents "mommy" and "daddy". This is not meant to cause harm to the biological parents, but merely to make the children more comfortable in their new home.
Of course, if a child refers to the foster parent in this way around their real parent, it may cause friction. It is worth pointing out to the child's actual parent that this is a common situation, and nothing to fret over.
Biological parents may also complain about the way their child is dressed, or anything else they can think of to discredit the foster parents. Occasionally, they will change the child's clothes or hair while on a visit or allow them to do activities or things the foster family may not allow in their homes. Be prepared and be patient; explain to the parent that while their child is under your care, you are entitled to make the decisions.
Remember, however, that in most cases, the biological parent deserve your empathy, not anger. They are lashing out at the caregiver because they feel that they have no way to fight the system that has taken away their child. To help smooth things over, try communicating with the biological parents before giving their child a haircut or allowing them to participate in a major activity. Or send requent, personalized notes and pictures so they can feel like they are still a part of their child's life.
This will lead to a better relationship for all and less stress for the children who are caught in the middle and only need to be loved.