What does Cosimo do in specific to the soldiers in the woods?

He lures the Austrians into traps, getting them so bug-bitten and crazy with being out of their element that any decorum they try to maintain dissolves. For the French, he reports the movements of the Austrians and suggests the best strategies for staving them off. His reputation grows among both camps, the Austrians spreading the rumor that the woods are full of Jacobins, and therefore rerouting themselves several times to steer clear. Among the French, he becomes their anonymous benefactor by covering them secretly with fleas and thereby inspiring them to delouse.