Although it is certainly not a requirement, it is HIGHLY recommended.  Aside from having the home in a clean, neutral, and pleasant condition, not being present for showings is one of the best things you can do.  You want to allow the buyers to see themselves and their families in the home.  This isn’t easy to do if another family is there.  Also, buyers should be able to speak freely with their agents so that they can talk through any questions or concerns in real-time.  This is especially important when a buyer sees multiple homes in a day and may have home buyers fatigue from all the showings.  Also, to the extent possible, dogs, cats, etc., should be secured.  If any special instructions need to be left for the Buyer’s Agent for showings, such as “do not let the cat out” or “the dog is locked in the basement,” we can do that through the MLS.