Background: The Cochrane Central Register of Controlled trials (CENTRAL) is a specialist register of electronic reports of trials focused on living human beings. Aims: To investigate whether animal studies hide in CENTRAL. Methods: We searched CENTRAL (Issue 1, 2009) using terms for animals in title and then the title, abstract, keywords combined function. The results were downloaded and manually searched twice to ascertain whether trial participants were indeed living human beings or animals. Results: At the time of writing this work is still ongoing. However, CENTRAL positively clucks moos, squeaks, meows and even barks with the sound of wildlife. Full data will be presented at the Colloquium. Conclusions: The proportion of animal studies in CENTRAL is small but indicative of how simple measures could be used to clean much irrelevant data from this important but flawed register.