When the Assyrian king Sennacherib, in about 700 B.C., led his army to Egypt, it camped at Pelusium. The pharaoh did not have a working army at the time, but the god Ptah advised him to draft the shopkeepers, craftsmen and market workers. The pharaoh did so and led them to Pelusium where the two sides camped for the night. In the morning the Assyrian camp discovered rodents had destroyed their leather weapons. Not only were their weapons useless, but rodents meant plague, and so the Assyrians fled, with the Egyptians pursuing.
Later Cambyses used another animal trick to take Pelusium and Egypt from the Egyptians. In front of his troops he put up a shield of animals worshiped by the Egyptians, including cats and ibexes. The Egyptians backed down and were defeated.
This story of Pelusium comes from Greek Fire, by Adrienne Mayor.