Is CPS law enforcement? No.
CPS caseworkers are employees of a county human-services department — not police officers. In general they cannot arrest you and do not carry police powers. Sometimes a police officer comes along on a visit, but the two roles are different, and knowing that changes the power in the room. You are not talking to law enforcement when you talk to a caseworker.
Can CPS come into my home?
Generally, a caseworker needs one of three things to enter your home: your consent, a court order (a warrant), or a genuine emergency. Without one of those, a parent can generally decline to let them in. Declining is a real option — though it can lead the county to seek a court order, and it's a fact-specific decision. Your rights when CPS comes covers the constitutional side (the Fourth Amendment) in more depth.
Do I have to answer their questions?
Generally, no — a parent can decline to answer and can ask to speak with a lawyer first. Not cooperating has trade-offs, and every situation is different, so it's worth understanding both before deciding. See Working With Your Attorney and Talking to Your Caseworker.
Can they interview my child?
CPS often interviews children — sometimes at school, without a parent present. This is a contested and fact-specific area of the law, and what a parent can do about it varies. An attorney can explain your options in your specific situation.
Can they take my child?
Generally, removing a child requires a court order, or a genuine emergency — and after an emergency removal, a prompt hearing must follow. See Your Rights in an Emergency Hearing for what happens next and the rights you have.
Can they make me take a drug test or do services?
Usually these come from either a voluntary safety plan you agree to, or a court-ordered treatment plan. Before a court is involved, many things are voluntary — which means a parent can ask questions, ask for changes, and consult a lawyer before signing. See How to Address Safety Concerns and Your Case Plan, Decoded.
The bottom line
Some things CPS can do. Some it can do only with your consent or a court's order. Some it cannot do at all. The power in that moment is not unlimited — and knowing which is which is your footing. When you're unsure whether CPS can really do something, that's exactly the question a licensed attorney answers.