1.
robots.txt can made private file not viewable by humans?

2.
if i have 1st robots.txt in primary domain ggg.com
www,ggg.com/robots.txt
if folder1domain.com is a secondary domain...
www,ggg.com/folder1/ === www.folder1domain.com, this latter root folder when accessed from www.folder1domain.com, should needed another robots.txt ???