How Does yahoo crawl a site?

Please, can some tell me how yahoo or even Google crawls one’s site and how fast instant ways for one’s site to be crawled on Yahoo
I got a site which frequently get crawled by Google for about three time but I get none from Yahoo though I have submitted my site to Yahoo search engines.

what you need to do is to get a Track code, and install it in your site, then create Sitemap and finally submit your site to Yahoo search engines

Have you implemented yahoo code in your site ? this code will be implemented in your index page which will allow yahoo search engine bot to crawl your site