When you receive a call from an unknown number, it's generally recommended not to answer it right away. Instead, use a specialized service called number lookup to find out who called you from this phone number. This service allows you to enter the number and obtain information about the caller, such as their name, location, and even comments from other users who have received calls from the same number. By using who called me from this phone number as a specific search query, you can easily identify the caller and decide whether it's worth returning the call or not. Remember, it's important to prioritize your safety and privacy when dealing with unknown numbers.