External disk in default scan

Recently installed Norton Security and very pleased so far.  But couldn't find an answer for this.  I have an external disk connected via USB 3 that is on whenever the computer is on.  It shows in Windows Explorer with a drive letter assigned just like any other disk.  Will the external disk be included in the Norton default 'Full System Scan' or should I create a Custom Scan explicitly including this disk to be sure it gets scanned.  Help appreciated.