The Sensor Relocation (SR) problem is an important issue in Wireless Sensor Networks (WSNs). For WSNs with an ongoing surveillance task, it is necessary to follow a strict response time requirement when relocating redundant sensors to the requesting places. In this study, we revisit the SR problem in mobile WSNs. The proposed algorithm can find the redundant sensor nearest to the requesting place with low message overhead. The performance evaluation done in this research has confirmed its superior performances.