I didn't include the following line of code in my head tag, however my favicon still appears in my browser:
<link rel="icon" href="favicon.ico" type="image/x-icon" />
If you don't call the favicon,
favicon.ico, you can use that tag to specify the actual path (incase you have it in an
images/ directory). The browser/webpage looks for
favicon.ico in the root directory by default.