DHS is the Department of Human Services. If DHS believes that a child is in danger, it is DHS’s job to investigate the situation and to take steps to protect the child.
If DHS wants to talk to you, you do not have to cooperate.
If you do, you should be aware that anything you tell DHS or the police can be used against you. But you should not do anything to get in the way of the investigation. If DHS is investigating you, it is a good idea to talk to a lawyer.