Pete & Paul: Our introduced friends. So why use two tiny introduced invertebrates? The answer is simple. These little Critters show the impact introduced species (no matter the size) can have on not only our natural environment, but our man made environments. Would you believe that this tiny invertebrate managed to shut down a major city train line? Don’t believe me? Read: The millipedes which stop trains. As humans, we need to understand the gravity of making changes. One small change in a fragile ecosystem can have significant impacts and we believe that Pete and Paul the Portuguese millipede’s represent this.