Abstract. We were inspired by the role of co-stimulation in the Biological immune system (BIS). We propose and evaluate an algorithm for energy efficient misbehavior detection in ad hoc wireless networks. Besides co-stimulation, this algorithm also takes inspiration from the capability of the two vital parts of the BIS, the innate and the adaptive immune system, to react in a coordinated way in the presence of a pathogen. We demonstrate that this algorithm is also applicable in situations when a (labeled) data set for learning the normal behavior and misbehavior is unavailable.