Limited sensor battery capacity is a major issue in wireless sensor networks. If all of the sensors in a network need not be in an awake state to provide adequate coverage at any given time, it is possible to strategically schedule their awake and sleep times to extend useful network lifetime. In this paper we present two heuristic methods for sensor scheduling using an Artificial Bee Colony metaphor. The methods maintain a threshold coverage level. The first method uses a fitness measure aimed at prolonging the network lifetime and the second method combines network lifetime with coverage. Both methods run until the coverage level fails to meet a threshold. Experiments show that both methods produce extended network lifetime. Comparisons are made with a method in which awake and sleep times are set randomly.