What are bots?
“Bots”, for those not familiar with the term, are basically computer programs that “surf” multiple websites to perform a variety of automated tasks. Examples of bots include those used by the search engines. Some bots go through your website looking for web forms and email addresses to send you spam. Other bots probe your website for security vulnerabilities.
Before you can block a bot, you will need to know at least one of two things: the IP address where the bot is coming from or the “User Agent string” that the bot is using. The easiest way to find this is to look into your raw web log.