百度爬虫
    * Baiduspider+(+http://www.baidu/search/spider.htm”)

google爬虫
    * Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google/bot.html)
    * Googlebot/2.1 (+http://www.googlebot/bot.html)
    * Googlebot/2.1 (+http://www.google/bot.html)

雅虎爬虫（分别是雅虎中国和美国总部的爬虫）
    *Mozilla/5.0 (compatible; Yahoo! Slurp China; http://misc.yahoo/help.html”)
    *Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo/help/us/ysearch/slurp”)

新浪爱问爬虫
    *iaskspider/2.0(+http://iask/help/help_index.html”)
    *Mozilla/5.0 (compatible; iaskspider/1.0; MSIE 6.0)

搜狗爬虫
    *Sogou web spider/3.0(+http://www.sogou/docs/help/webmasters.htm#07″)
    *Sogou Push Spider/3.0(+http://www.sogou/docs/help/webmasters.htm#07″)

网易爬虫
    *Mozilla/5.0 (compatible; YodaoBot/1.0; http://www.yodao/help/webmaster/spider/”; )

MSN爬虫
    *msnbot/1.0 (+http://search.msn/msnbot.htm”)