Guard goose

[5] Canada geese in Cincinnati parks have been responsible for knocking people down and breaking their bones, and called "spitting, hissing, biting attack missiles".

In ancient Rome, geese are credited by the historian Livy for giving the alarm when Gauls invaded (see Battle of the Allia).

[13] They are reported to have been used to guard United States Air Defense Command installations in Germany;[14] as the Scotch Watch at Ballantine's Distillery in Dumbarton, Scotland;[15][16] and to protect a police station in Xinjiang, China.

[7][17][18] Due to their tendency to make noise when approached by strangers, about 500 geese were used to supplement dogs, drones, and humans to patrol the 533-km boundary between Chongzuo and Vietnam during the COVID-19 pandemic.

[19] Guard geese are utilized to monitor the fence at prisons in Brazil for incursions because of their low cost, and the fact that they don't respond to food bribes like dogs.