The trained bird can then easily train a whole flock.
I have long thought it would be funny to train birds to attack the little flags that you see on limousines that carry foreign dignitaries. Then release a flock of trained birds during some public event.
Maybe Danville, IL
http://articles.chicagotribune.com/2013-01-26/news/ct-met-cr...
Or Terre Haute, IN
http://www.nytimes.com/2011/10/27/us/terre-haute-battles-cro...
The project was canceled after one or more buildings on the base they were being trained burned down.
Incendiaries were attached to bats, who were dropped from planes. And then expected to fly into buildings. Incendiaries go off. Building burns down.
Pigeons were used as the guidance system in an early smart bomb. Rather than tracking a target with a laser or GPS, trained pigeons would steer the bomb.
Never used in combat, but supposedly very, very effective. Strap time-delayed incendiary bombs to hibernating bats, put them in a bomb case, release them over Japan. The bats go hide in buildings and start 1000s of fires.
[1] https://www.theguardian.com/world/2016/sep/12/eagles-v-drone...
Participants: Emus, Sir George Pearce, Major G.P.W. Meredith, Royal Australian Artillery