Geese are considered to have excellent eyesight In another case, several geese protecting their goslings knocked a man off his bicycle, resulting in hospitalization. One Buffalo, New York resident claimed over $2 million in damages for a goose attack while on a neighbor's property. At times, park rangers have killed entire flocks of aggressive geese.
Canada geese in Cincinnati parks have been responsible for knocking people down and breaking their bones, and called "spitting, hissing, biting attack missiles". The same aggressive, territorial behavior can be utilized in the guard capacity. Geese are intelligent enough to discern unusual people or sounds from usual stimuli. Their loud honking will alert humans when the geese are alarmed. ==History of use==