The Mongols not only took advantage of such trickery, but in their relentless use of propaganda, they spread stories to foment anxiety and fear among the enemy.
In one apocryphal account circulated to create anxiety among the enemy, the Mongols supposedly promised to retreat from a besieged city if the Jurched defenders would give them a large number of cats and birds as booty.
According to the story, the starving residents eagerly gathered the animals and gave them to the Mongols.
After receiving all the birds and animals, the Mongols attached burning torches and banners to their tails and released them, whereupon the frightened animals raced back into the city and set it on fire.
The story supplied a dramatic dose of war propaganda.
from Jack Weatherford's 'Genghis Khan and the Making of the Modern World'
https://www.amazon.com/dp/B000FCK206