Jocelyn, a friend from both SEO Chat and SEO Guy forums, has created a log file analyzer called Bothunter. It is a good tool for digging through your log files and finding all the nuggets of information that you need to know, such as which bots came to your site and what they did once they got there, which search engines are sending traffic to you, and for which keywords, and much more. If your stats program is not giving you the information you need, see if Bothunter works for you.