I'm pretty new to this game, but I think that is the general idea behind the "minor races" - those whose flags are just a solid color rectangle with no design. They have some spaceflight capability, but never leave their home system. They are very easy pickings, even for a newbie like me.
[This message has been edited by taterbill (edited 12 February 2001).]
There are no such races in the game.
It should be easy to make though, just take a neutral and give it a vehicle_construction_AI.txt file with all the entries for colony and other ships removed.