Pigeon's can be trained, and can easily be bred in large numbers.
Train them to fly towards, and into the Enemy standard's (as in the design on their shields etc).
Strap a small contact bomb of Greek fire or gunpowder to them.
Hey presto! Killer birds, enemies killed by explosion, and none of that tedious mucking around figuring how to cast a cannon. Ideal for the Middle Ages.
Consider an early version of the Pigeon Guided Missile - http://en.wikipedia.org/wiki/B._F._Skinner#Pigeon_Guided_Missile
Train them to fly towards, and into the Enemy standard's (as in the design on their shields etc).
Strap a small contact bomb of Greek fire or gunpowder to them.
Hey presto! Killer birds, enemies killed by explosion, and none of that tedious mucking around figuring how to cast a cannon. Ideal for the Middle Ages.
Consider an early version of the Pigeon Guided Missile - http://en.wikipedia.org/wiki/B._F._Skinner#Pigeon_Guided_Missile