Kraits are a group of highly venomous snakes found in parts of tropical Asia from Iran through the Indian subcontinent into the jungles of Borneo. There are 16 recognised species, with eight species from India and several more listed as subspecies.
Kraits are nocturnal and typically have a non-aggressive demeanour. Yet, they are among the most medically important snakes, particularly in India, as they have the most toxic venom among terrestrial snakes found on the Indian subcontinent. The common krait (Bungarus caeruleus) is listed among the “Big Four” of Indian venomous snakes, along with the spectacled cobra, saw-scaled viper and Russell’s viper. Together, these snakes are responsible for over 50,000 reported annual deaths from snakebites in India.
Kraits closest relatives are cobras, believed to have broken off from a common ancestor during the Miocene, about 10.2 million years ago. Fossil evidence was discovered in the Potwar Plateau in the Siwaliks in present-day Pakistan, as reported by Head et al. in 2016 in a paper in the journal Palaentologica Electronica.
Interestingly, both their evolutionary origin and their common and genus names are tied to India. The common name, krait, stems from the Hindi word “karait”, meaning black. The genus name, Bungarus, stems from the Telugu word, “Bungarum”, meaning gold. One would wonder how the two names for the same group can mean two distinct colours; the answer is that the names go back to the regions where the species were described. It turns out that the banded krait (Bungarus fasciatus) with its prominent gold bands was used to coin the genus name, while the word krait must have come from the Hindi heartland of Central India where the predominantly black common Indian krait (B. caeruleus) is encountered.
Kraits are medium to moderately large and often measure up to a meter in length. Nocturnal in habit, they forage slowly on the ground and among leaf litter. Adult kraits are known to feed on mice, snakes, and lizards, but we don’t know much about the diet of juveniles. All species lay eggs, often in a burrow. Despite being feared and of medical importance, we know very little about kraits, but here’s what we do know about our fascinating, feared, and fanged friends.