TL;DR see the comments to my article. If they don't contain my captcha, it is a bot and you can flag it, then click "MUTE" to mute it for you, too.
I noticed some comments on my last posting which seems to be from bots. So let's test how smart they are. Please don't use the word "nice", "upvoted" or "thanks" in your comment, and if you comment, tell me the result of 2+5. If you don't, you are a bot and you've been catched :-) Then I can downvote the comment, which allows me (and others) to mute the bot.
But not all bots are bad. I like the isaac.asimov bot, which evaluates your article and tells you the Flesch-Kincaid grade level of it.
PS: clipart from http://www.clipartlord.com/2014/09/04/free-cute-cartoon-robot-clip-art/