Females with young are especially defensive. Feeding wild animals makes them dependent on people. Animals often bite the hand that feeds them. Do not feed wildlife, including ground squirrels and birds. Do not harass wildlife.
Harassment is any human action that causes unusual behavior or change of behavior by an animal.
Repeated encounters with people have cumulative results including stress and behavior changes, such as avoidance of an essential feeding area after frequent approach by people. For wildlife, raising young is a private affair. Nesting birds are easily disturbed. If an adult on a nest flies off at your approach, or circles you or screams in alarm, you are too close to the nest. Unattended nestlings readily succumb to predation and exposure to heat, cold and wet weather.