Not recommending this tool in particular 9assume the stats could be recovered from site log files....but would be of interest to know how far google spiders & how often it shallow v deep crawls...

If you're interested in tracking spider traffic, Robot Manager Pro
is a killer program. It's a lot of fun to see how many times
Googlebot, for example, visits your site in a month, and how far
down into your site the spider crawls.
http://www.websitemanagementtools.com/robot.html