FortiView Bot Analysis
Go to Dashboard > FortiView Bot Analysis. If it's not available in the Dashboard menu, refer to Monitors for how to add a monitor.
Bot Analysis displays statistics on access by search engine indexers and malicious bots such as DoS, Spam, Crawler, etc. Statistics are gathered by DoS prevention in anti-DoS rules,and Configuring known bots. Based on this data, if an automated tool is abusing access, you can configure rate limiting with such as Custom Policy.
You can view information on the number of search engines and malicious bots in certain time periods. Click the pie chart, and you can view the second level of one malicious bot.