Mozilla Developer Network. Easy PHP Blackhole Trap with WHOIS Lookup for Bad Bots. One of my favorite security measures here at Perishable Press is the site’s virtual Blackhole trap for bad bots.
The concept is simple: include a hidden link to a robots.txt-forbidden directory somewhere on your pages. Bots that ignore or disobey your robots rules will crawl the link and fall into the trap, which then performs a WHOIS Lookup and records the event in the blackhole data file. Documentation. Spritely is a simple plugin with only two key methods, sprite() and pan() both of which simply animate the background-image css property of an element.
The difference between the two is that a 'sprite' image contains two or more 'frames' of animation, whereas a 'pan' image contains a continuous image which pans left or right and then repeats. Typically, in either case, you would use a png file (with or without transparency) for this. You might wish to use a transparent gif for Internet Explorer 6, though it probably won't look as good. Code Snippets.