Over the past decades, large amounts of data about carabids have been collected in the Netherlands, initially for the purpose of creating distribution maps for the country. In addition to information from collections and faunistic publications, a significant amount of data came from ecological studies using pitfall traps. Because of the rich tradition of carabidological research in the Netherlands, an exceptionally large database of these pitfall data is available. The database is a mix of approximately 1,500 short-term samples and circa 4,400 so-called 'year-samples', for which pitfalls were...