Radio Frequency IDentification (RFID) technology is increasingly being used to uniquely identify objects. An important component of RFID systems is the design of the antenna - which usually takes the form of a compacted meander line. This task becomes an optimisation problem as different designs will have different efficiencies and resonant frequencies. In this paper, we explore the use of a multi-objective version of ant colony system. This constructive meta-heuristic, as shown, is highly suitable for this problem.