I disagree. They can't remove the children without a court order in which the court believes the children are in danger. The family doesn't have to do ANYTHING that CPS requests.
Actually many states have time periods which are normally in the administrative code.
As you know, the difference between responding to CPS requests and refusing cooperation can translate into the difference between an informal resolution and having to go to court for a protective services case. When you don't want to comply with CPS instructions, it makes sense to 'lawyer up'.