They would only need to be listed as drivers if they live in your household and/or drive the truck on a "regular" basis. Most companies consider "regular" use as 12 times or more per year. If they borrow the truck
less than that frequency and they don't live with you then listing them should not be necessary. Keep in mind that a trip to and from the store is considered using the vehicle twice in the eyes of most insurance companies. While this is a general guideline, you may not be required to list them on your policy if the frequency that they use the vehicle is minimal.