One thing i've yet to hear asked..

saberx

How come the aliens are unable to remove a building?  I can't tell you how many times I've gotten stuck either making a building, or trying to get through a glogged passage way.  Also, it's annoying when someone builds the wrong chamber at the start and you can't do anything about it until you get another hive.

It would be nice to allow the person who built the structure to destroy it if he so chooses.