BotBlocker is a free WordPress plugin that tackles spam bots. Many anti-spam plugins frustrate commenters by asking them to enter CAPTCHA codes or answer questions. Botblocker works differently by tricking the spam bot to perform actions that a human couldn’t do (known as honeypot technology).
The plugin works right out of the box though there are a number of settings you can change. There are three different methods available that you can use to detect spambots. The smart option chooses a random word from a long list of decoy fields such as address2 and newsletter. The static method allows you to use a set name for a field every time. The random method generates a random string of alpha-numeric characters that changes daily.
It isn’t clear what the best method is. I’d recommend choosing one and then switching if you are still having problems with bots. When a spambot is detected you can either block it so the comment is never submitted or allow the comment and either flag it as spam or put it into the comment moderation queue. You can also set where the error message is displayed or stop an error message from being displayed. Error messages can be customised if you do choose to display them.
In order to fool the spambot but not frustrate anyone else, the honeypot field has to be hidden from real visitors.
Another cool thing BotBlocker does by default is switch the name and email fields for the spambot so that bot will submit a name into the email field and WordPress will reject it as an invalid email. This can be switched off if you wish.
I tried out Botblocker on my test blog but I’ve not used it on a live website. I am a big fan of anti-spam plugins that don’t annoy commenters with tests or require additional fields to be entered (as this discourages many people from leaving comments). If you have been having a problem with spam on your website recently, it could be worth trying BotBlocker out before other solutions that require users jump through hoops.