Bot Detection with PHP
Bots or Crawlers, are basically search engines crawling around the internet. This is how you get your pages on search engines (well, a major way). Bot Detection isn’t something super vital, but if your CMS or website already has practically everything, then you need Bot Detection.
Really Bot Detection isn’t as difficult as you might guess. The SERVER variable $_SERVER['HTTP_USER_AGENT'] has in it a lot of cool info on the visitor such as the Browser they are using and if it’s a bot/crawler, the name of the Bot.
Link: Bot Detection with PHP
BS most of $_SERVER values can be easy faked. And HTTP_USER_AGENT is one of them!