诡异的 favicon.ico

[laoona]

每次页面发起 ajax 请求，都会自动带一个 favicon 的请求粗来。而且 favicon 的请求，还带一个随机的请求参数。有什么办法，可以屏蔽吗？

favicon 的请求：
Request URL:http://localhost/favicon.ico?_=160292631
Request Method:HEAD
Status Code:200 OK
Remote Address:127.0.0.1:80

favicon 的请求头：
Accept:/
Accept-Encoding:gzip, deflate, sdch
Accept-Language:zh-CN,zh;q=0.8,en;q=0.6,zh-TW;q=0.4
Connection:keep-alive
Cookie:r=6C616F6F6E6F; PHPSESSID=8jj4fco8eo7rjjriqepajj89l0; saltkey=4Ozdj3zWs5ifxPu2leg
Host:localhost
Referer:http://localhost/dinner/booking
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.116 Safari/537.36

favicon 的响应头：
Accept-Ranges:bytes
Cache-Control:max-age=2592000
Connection:keep-alive
Content-Length:13790
Content-Type:image/x-icon
Date:Wed, 09 Mar 2016 03:29:53 GMT
ETag:"5678a65d-35de"
Expires:Fri, 08 Apr 2016 03:29:53 GMT
Last-Modified:Tue, 22 Dec 2015 01:24:45 GMT
Server:nginx/1.9.0

PS:提问怎么发截图？