In many situations involving deployment of a sensor network, far more sensor units are available than necessary for simple coverage of the space. Adding sensor mobility can exploit this redundancy by repositioning sensors to mitigate sensor failure and to enhance the group?s sensing capabilities. When events occur frequently in particular areas, a higher data resolution in that area, and hence more sensors, would be preferable. So, the sensors should move to these areas reactively. Two distributed algorithms let mobile sensors react to events such that the distribution of the group of sensors tends toward the distribution of the sensed events. These algorithms use minimal communication and computation. Several extensions to these algorithms maintain approximately complete coverage of the environment while still converging on the event distribution. The coverage techniques vary in the amount of computation and communication required.