To study how a social group, such as an ant colony, monitors events occurring throughout its territory, we present a model of a network of patrolling ants engaged in information collection and dissemination. In this network, individuals follow independent paths through a region and can exchange signals with each other upon encounter. The paths of the ants are described by correlated random walks. Through simulations and analytic approximations, including a new approach to the spatial logistic equation, we study the efficiency with which such a network discovers a constantly changing stream of "events" scattered throughout the region and the speed with which information spreads to all ants in the network. We demonstrate that efficiency of event discovery and the speed of information spread are enhanced by increased network size and straighter individual ant paths, and that these two effects interact. The results lead to predictions regarding the relations among species-specific movement patterns, colony size, and ant ecology.