1. A wireless sensor network (WSN) data processing system node configured for information swarming, the system comprising: a host computing device comprising at least one processor and memory and communicatively coupled to a plurality of nodes in the WSN and an aggregation point receiving data collected by the nodes in the WSN; a data acquisition module coupled to a sensor and executing in the host computing device, the data acquisition module acquiring data sensed by the sensor; a data overhearing module also executing in the host computing device, the data overhearing module overhearing relay data transmitted along a relay path exclusive of the WSN data processing system node from an originating one of the nodes in the WSN to the aggregation point in the WSN; and, a swarming module coupled to both the data acquisition module and the data overhearing module and executing in the host computing device, the swarming module comprising program code configured to determine a relevance of relay data overheard by the data overhearing module in reference to at least one relevance rule, and to forward additional data acquired by the data acquisition module to the aggregation point over the WSN in response to determining the relay data to be relevant.