Some years ago I found out that snails and slugs are not the same animal species. In English this doesn't really make sense because they have different names, but in Dutch we call them by the same name, only refer to slugs as the 'naked' ones (snail = slak, slug = naaktslak). I thought it was perfectly logical that they were indeed the same animal species, but that slugs had at some point decided to abandon their houses/shells. My observations made this a straightforward conclusion as I had encountered on different occasions: snails with houses, snails without houses (slugs) and just empty houses. The real question, of course, was why they would leave their house behind. Did they outgrow them? Did they leave them as they reached adulthood, thus claiming their independence? Or were they too proud of their slimy bodies to conceal them? Perhaps slugs are actually the proudest creatures on Earth. Such questions might seem pointless to some, but for me they worthwhile asking.