Various experiments have shown that the performance of wireless sensor networks is very hard to predict. It is also acknowledged that deploying sensor networks in real settings is a difficult and tedious task. To contribute to the understanding of wireless sensor network behavior we report on our experience from two recently deployed sensor networks: one in-door surveillance network in a factory complex and a combined out-door and in-door surveillance network. Both networks use advanced sensor network technology such as ad hoc routing and multi hop networking. Our results highlight the need for self-configuration in wireless sensor networks, especially in cases where fast deployment and dynamic environments are important aspects.