How do I stop Spam harvesters?

I currently have a known Spam Harvester causing multiple errors in my templates css folder. Is there some way of preventing Spam Harvesting (bots?) like this, from snooping through my css folder? A htaccess solution would be ideal, but I need an example to go by. Thanks.

Google for the issue and examples

"Google for the issue and examples "
Of course I've done that...but found nothing specific to zen-cart.
I have put a reference not to index the Includes folder, in the robots.txt, but I doubt they'd take that advice.
I'd like to block access to the Includes folder, by htaccess,(as that would sort out the problems i'm having) but I still want to keep the cart functional. I've already denied access to the offending IP but I want a solution for the next one that comes along.Any ideas anyone?

The only way to completely stop spam harvesters is not to run a website.

Vger