Typical robot behavior is to visit the top-level page first. They are programmed to space their requests out to avoid overloading any server with their activity. I took the time to track their course through a new multi-level site with about 50 pages by analyzing the log files for requests from known robot IP addresses. I only submitted the index.htm page, and had all the proper robot bait in place before I submitted. Within the week, there were requests for the pages linked from the index page, and they hit the third level pages by the end of the fortnight.
Frames make it VERY difficult for robots and repeat visitors.
Neither one can set bookmarks and jump back to where they want to go after leaving the site. Unless you have an absolutely overwhelming need for frames, they are more trouble than they are worth. Within this site, it explains how to track down robot visitors.