How do I move objects automatically with no input?

Sorry if the thread title is confusing. I am trying to make a simple game where walls with different holes come at the player, and you have to press buttons on the keyboard to orientate your limbs in different ways so that you can fit through the holes. My problem is that I don't know what to do to get the walls to actually move at the player. I have a navmesh baked already, and the walls are a navmesh agent, but I have no idea where to go from there. I have tried looking at the documentation already but I couldn't figure it out through there, thanks!

 

I don't think that's a "correct" use of the navigation system. Check out the Space Shooter tutorial series -- it sounds like you may benefit from the way he sends waves of asteroids at the player's ship.

http://unity3d.com/learn/tutorials/projects/space-shooter-tutorial