This paper addresses the problem of data acquisition in ad hoc and sensor networks with mobile sinks and proposes a protocol based on swarm intelligence, SIMPLE, to route data in such environments. The proposed protocol is based on a swarm agent that integrates the residual energy of nodes into the route selection mechanism and maximizes the network's lifetime by evenly balancing the residual energy across nodes and minimizing the protocol overhead. The protocol is robust and scales well with both the network size and in the presence of multiple sinks. An information theoretic lower bound on the protocol overhead associated with the swarm agent advertisement is obtained. Simulation results are used to verify SIMPLE's performance.