Description While most colubrids are non-venomous -LRB- or have venom that is n't known to be harmful to humans -RRB- and are normally harmless , a few groups , such as genus Boiga , can produce medically significant bites , while the boomslang and the twig snakes have caused human fatalities .

While most colubrids are non-venomous -LRB- or have venom that is not known to be harmful to humans -RRB- and are normally harmless , a few groups , such as genus Boiga , can produce medically significant bites .
