Chrome putting itself in the Dock whenever it wants.

So I have Google Chrome installed on my Mac & randomly it will put itself in my dock, where it normally doesn't reside. It is usually about every two weeks or so, but sometimes its within a few days. It is the only application to do so. It puts itself as the first application (immediately after the finder) regardless of what else is on the dock. Of note: I rarely use Chrome as I usually prefer Safari or Firefox. I may open it once every few months. I can't seem to find anyone else who has had this problem. Suggestions?

Make sure the chrome auto updates are not running - it could be adding itself back when it checks for updates.