I use a free statistics site to manage my website's visitor stats. I've been noticing for the past couple weeks, one visitor that would come to the main page of the site and leave, without clicking on any of the links on the page or anything. What worries me is that this goes on every single day between 5 - 20 times a day. I'm not really complaining because bandwidth isn't a concern, but I worry that this may be some sort of red flag for a malicious attack. Is there need for worry? I have the IP and hostname of the visitor, which gives me the location. Still, I don't know if I should take any action or just hang back and watch. What should/n't I do?