Above is good advice. But you don't have to have a lawyer on standby, not a bad idea but not required. If the cops ask for permission to enter, they really are asking. If they are coming in anyway, you'll know that as well. Family services differs from stated to state, they are the ones that were the main "force" in this raid. 4th doesn't apply to them, or to cops acting as their agents in a purely escort fashion. Always remember though that the rules can't be reversed. If the police use family services to try to get them in, the 4th applies due to family services being an agent of the man at that point.
Always exceptions out there, but good rule of thumb.