Evolutionary Computation niching methods, such as Fitness Sharing and Crowding, are aimed at simultaneously locating and maintaining multiple optima to increase search robustness, typically in multi-modal function optimization. Such methods have been shown to be useful for both single and multiple objective optimisation problems. Niching methods have been adapted in recent years for other optimisation paradigms such as Particle Swarm Optimisation and Ant Colony Optimisation. This paper discusses niching techniques for Ant Colony Optimisation. Two niching Ant Colony Optimisation algorithms are introduced and an empirical analysis and critical evaluation of these techniques presented for a suite of single and multiple objective optimisation problems.