In this paper, we present a real application system based on wireless sensor network (WSN) for fence surveillance which is implemented on our development platform for WSN, called ANTS (An evolvable Network of Tiny Sensors). Our system, called the WFS system, is expanded to connect and control a robot (UGV/UAV) and a camera sensor network for the purpose of fence surveillance. Two kinds of sensor nodes, ground nodes and fence nodes, are deployed and collaborative detection is performed and the result is reported to the base station (BS). The BS does not only give a control message to the camera to show the place where an event has occurred, but it also issue orders to the robots to extend the communication distance of the system, to approach and sense the object more precisely, or even to attack an enemy autonomously. This paper describes various techniques and know-how to fulfill a WSN-based integrated surveillance system. A new adaptive threshold algorithm to detect intruders is prop...