Distributed sensor networks (DSNs) consisting of many small, low-cost, spatially dispersed, communicating nodes have been proposed for many applications, such as area surveillance and environmental monitoring. Trends in integrated electronics, such as better performance-to-cost ratios, low-power radios, and microelectromechanical systems (MEMS) sensors, now allow the construction of sensor nodes with signal processing, wireless communications, power sources and synchronization, all packaged into inexpensive miniature devices. If these devices can be easily deployed and self-integrated into a system, they promise great benefits in providing real-time information about environmental conditions. Intelligent sensor nodes function much like individual ants that, when formed into a network, cooperatively accomplish complex tasks and provide capabilities greater than the sum of the individual parts. The paper discusses several technical challenges that must be overcome to fully realize the viability of the DSN concept in realistic application scenarios.