You have waited 18 years for your child to go to college. Now, the question is whether you need special coverage while they are in a dorm or apartment. If your child is living in college sponsored housing, your home policy will provide protection for their personal belongings AND liability protection.
As soon as you child rents an apartment, you MUST secure a separate renters insurance policy. The definition of an insured premise under your home policy will NOT include this new, separate residence. Securing the renters coverage will provide the same protection for their personal belongings and the MOST important coverage, liability.
Having this separate renters policy also isolates any potential losses from your home policy. Typically, there is also a lower deductible.