In 244 BCE, Hamilcar transferred his army at night by sea to a similar position on the slopes of Mt. Eryx (Monte San Giuliano), from which he was able to lend support to the besieged garrison in the neighbouring town of Drepanum (Trapani). Hamilcar seized the town of Eryx, captured by the Romans in 249 BCE, after destroying the Roman garrison, and positioned his army between the Roman forces stationed at the summit and their camp at the base of the mountain. Hamilcar removed the population to Drepana. Hamilcar continued his activities unhindered from his position for another two years, being supplied by road from Drepana, although Carthaginian ships had been withdrawn from Sicily by this time and no naval raids were launched. During one of the raids, when troops under a subordinate commander named Bodostor engaged in plunder against the orders of Hamilcar and suffered severe casualties when the Romans caught up to them, Hamilcar requested a truce to bury his dead. Roman consul Fundanius (243/2 BCE) arrogantly replied that Hamilcar should request a truce to save his living and denied the request. Hamilcar managed to inflict severe casualties on the Romans soon after, and when the Roman consul requested a truce to bury his dead, Hamilcar replied that his quarrel was with the living only and the dead had already settled their dues, and granted the truce.

The actions of Hamilcar, and his immunity to defeat, plus the stalemate at the siege of Lilybaeum caused the Romans to start building a fleet in 243 BCE to seek a decision at sea. However, the constant skirmishing without ultimate victory may have caused the morale of some of Hamilcar's troops to crack and 1,000 Celtic mercenaries tried to betray the Punic camp to the Romans, which was foiled. Hamilcar had to promise considerable rewards to keep the morale of his army up, which was to produce near fatal problems for Carthage later on.