A few months ago I opened a post to talk about the same since a friend of mine they were using bots over the plan he had hired.
Excessive traffic Googlebot
Try changing the crawl rate of Googlebot:
Webmaster Tools> Settings> Crawl rate> Limit the maximum frequency tracking Google> Bass> Save
See if it works for you, my friend ran him.
Anyway, in CPanel Awstats take a look at the "Guided Robots / Spiders" and bot will tell you what exactly it is that you are consuming the entire width, if it is to Google, Bing, etc.