Black-tailed skimmers emerge between May and July and can be seen throughout the summer and into early September. Black-tailed Skimmers spend two to three years as larvae, usually living in still or slow moving water. When the adult is ready to emerge the larvae can travel some distance over land before finding a suitable site to cast their larval skin. Once mature, adults return to water to breed and males can be fiercely territorial. After mating, females egg-lay by dipping the tip of their abdomen into the water as they fly over it.