Can persons in a State of Nature agree to a social contract defining the rights of that newly formed society?
Yes but it needs to be explicit. It may be that if I go into a restaurant and order a hamburger, I'm implicitly agreeing to pay for it but simply existing on my property isn't implicit consent of being governed.
Is living in a state implicit consent to be governed and if not why. Maybe I'm a little dense but I'm not sure how the restaurant analogy applies to a broader social contract.