What would cause this?

Hi gang: I have a question regarding php and security. My apologies beforehand if this is common knowledge to everyone except me. I have a php application sitting at root level on one of my servers who's sole function is to send me an email whenever it's run. So, whenever I reference this app, it sends me an email -- very simple. However, the app isn't reference or linked anywhere on the site, but it still occasionally runs all by itself. My question is -- what's triggering it? Is the cause a bot of some type? I was told that spiders/bots could only travel links outward from your front page (i.e., index) to all other referenced pages, but could not access things that are not linked -- unless of course they know the name of the app. So, why does this php app occasionally run? Are there critters that navigate my root without my knowledge? Thanks. tedd -- ------------------------------------------------------------------------------------ http://sperling.com http://ancientstones.com http://earthstones.com