sitemap generation each day and Google bot issue

My sitemap keeps getting re-generated each day. Then, I keep getting the google bot to visit each day. it is killing my bandwidth.

I turned off automatic google and Yahoo notification, but not sure that is what I want to do. How can I just have google visit once a week like my settings depict?

But google is the #1 and #3 user of my site. Double the traffic of my next most frequent user #4.

1 43644 6.82% 42693 7.86% 1934582 15.46% 1 0.01% crawl-66-249-71-139.googlebot.com 2 33663 5.26% 29007 5.34% 1430274 11.43% 7 0.04% spider13.yandex.ru 3 28835 4.51% 22901 4.22% 771454 6.16% 12 0.07% crawl-66-249-71-147.googlebot.com 4 23017 3.60% 20756 3.82% 273959 2.19% 494 3.08% rrcs-24-39-1-242.nys.biz.rr.com

So why is Google hitting my site so much?