Getting down low, or being at eye level with your subject, creates a more intimate and personal connection in the final image. This often means getting down and dirty, but once you start doing it this way, you won't be able to do it any other way.

A black headed gull targets a piece of bread. If this was taken from a standing position, or even a sitting position, the depth of field would have been much deeper and the "personal" connection with the gull would be lost.