:::How do you know it's a google bot?
The IP address.
freshBot: 64.68.82.* bah, listed for only a few days, short dinner date then it dumps you.
deepcrawler: 216.239.46.* Good bot, it likes you, listed until death do you depart. So don't make him mad or it will divorce your site. You can divorce the Googlebot by using your robot.txt file. It's much cheaper and faster than going to the courts.
It almost crashed my server once, taking the server load up to 24.56, 10.49, 5.14 slowing the server down for about five minutes!!