A colubrid (from Latin coluber, snake) is a snake that is a member of the Colubridae family. It is a broad classification of snakes that includes well over half of all snake species on earth. A colubrid's body is almost completely covered in scales. While most colubrids are non-venomous (or have venom that is not known to be harmful to humans) and are normally harmless, a few groups, such as genus Boiga, can produce medically significant bites. In addition, the Boomslang and African Twig Snake have both caused human fatalities.The venom-injecting fangs associated with venomous colubrids are almost always in the back of the mouth, compared to vipers and elapids. The Colubrids are certainly not a natural group, as many are more closely related to other groups, such as elapids, than to each other. This family has classically been a dumping ground for snakes that do not fit anywhere else. There is on-going mitochondrial DNA research which will sort out the familial relations within this group.