Plutarch, Fabius Maximus
Bernadotte Perrin, Ed.

11. But Minucius regarded all this as an old man's dissimulation, and taking the forces allotted to him, went into camp apart by himself,¹ while Hannibal, not unaware of what was going on, kept a watchful eye on everything. Now there was a hill between him and the Romans which could be occupied with no difficulty, and which, if occupied, would be a strong site for a camp and in every way sufficient. The plain round about, when viewed from a distance, was perfectly smooth and level, but really had sundry small ditches and other hollow places in it. [2] For this reason, though it would have been very easy for him to get possession of the hill by stealth, Hannibal had not cared to do so, but had left it standing between the two armies in the hope that it might bring on a battle. But when he saw Minucius separated from Fabius, in the night he scattered bodies of his soldiers among the ditches and hollows,² and at break of day, with no attempt at concealment, sent a few to occupy the hill, that he might seduce Minucius into an engagement for it.

[3] And this actually came to pass. First Minucius sent out his light-armed troops, then his horsemen, and finally, when he saw Hannibal coming to the support of his troops on the hill, he descended into the plain with all his forces in battle array. In a fierce battle he sustained the discharge of missiles from the hill, coming to close quarters with the enemy there and holding his advantage, until Hannibal, seeing that his enemy was happily deceived and was exposing the rear of his line of battle to the troops who had been placed in ambush, raised the signal. [4] At this his men rose up on all sides, attacked with loud cries, and slew their foes who were in the rear ranks. Then indescribable confusion and fright took possession of the Romans. Minucius himself felt all his courage shattered, and looked anxiously now to one and now to another of his commanders, no one of whom dared to hold his ground, nay, all urged their men to flight, and a fatal flight too. For the Numidians, now masters of the situation, galloped round the plain and slew them as they scattered themselves about.