Mago thought that it would be an excellent moment to attack the Romans while actually engaged in making their camp; he therefore rode up to the entrenchment with the greater part of his own cavalry and Massanissa with the Numidians, persuaded that he should catch Scipio off his guard. Scipio had however all along foreseen this, and had placed some cavalry equal in number to those of the Carthaginians under cover of some hills. Upon these making an unexpected charge, many of the enemy’s horsemen at once took to flight at the startling appearance, and began to make off; while the rest closed with their opponents and fought with great gallantry. But the Carthaginians were disconcerted by the agility of some of the Roman horsemen in dismounting, and after a short resistance they retreated with considerable loss. The retreat was at first conducted in good order: but as the Romans pressed them hard, they broke up their squadrons, and fled for safety to their own camp. This affair gave the Romans better spirits for engaging in a pitched battle, and had the contrary effect on the Carthaginians. However, during the next few days they both drew out on the intervening plain; skirmished with their cavalry and light-armed troops; and, after thus trying each other’s mettle, were resolved to bring the matter to the test of a general engagement.