does this also stop search engines seeing your pages

If anonymous users cannot see a content type because they do not have permission due to content access, i.e. anyone not logged into the site, does that mean that google/bing will not be able to index those pages too or do i need to put into my robot.txt something stopping them indexing the pages that I do not want anonymous users to access?

Basically, I want to have private information available to those people logged into the site and not for anyone else. Does content access do this?