In many applications such as precision agriculture (fruit tree plantation, olive groves) or environmental monitoring, wireless sensors are, very often, randomly scattered in the 3D area of interest. Such applications require full three-dimensional coverage. Undoubtedly, an initial random deployment does not achieve neither full coverage of the 3D area of interest, nor network connectivity. Thus, a redeployment algorithm has to be introduced in order to ensure these two goals. Our contribution is the design of 3D-DVFA, a distributed deployment algorithm based on virtual forces in three dimensional wireless sensor networks where sensor nodes are assumed to be mobile and autonomous.