Blue krait
The Common krait (Bungarus caeruleus ) is a highly venomous snake native to the Indian subcontinent. It is a member of the "big four" species, inflicting the most snakebites on humans in Bangladesh and India.
The coloration of this snake is generally black or bluish-black, with about 40 thin, white crossbars which may be indistinct or absent anteriorly. Albino specimens can be found, although such cases are extremely rare. The pattern, however, is complete and well-defined in the young, which are marked with conspicuous crossbars even anteriorly; in old individuals, the narrow white lines may be found as a series of connected spots, with a prominent spot on the vertebral region. A white preocular spot may be present; the upper lips and the belly are white. Males of this species are typically longer, with proportionately longer tails.
Common kraits are distributed from Sindh to West Bengal, throughout South India and Sri Lanka. They have also been recorded in Afghanistan, Bangladesh, and Nepal. These snakes live in a wide variety of habitats, including fields and low scrub jungle, semi-desert, rocky areas, and oven ventures to plantations, cultivated land, suburban gardens, and settled areas. They rest in termite mounds, brick piles, rat holes, and even inside houses. Common kraits are frequently encountered in water or in proximity to a water source.
Common kraits are solitary and can be active both during the day and night time. During the day, they are sluggish and generally docile. They often hide in rodent holes, loose soil, or beneath debris, so are rarely seen. They often roll their body into a loose, coiled ball, keeping their head well concealed. When in this 'balled' condition, the snake allows considerable handling, but overhandling often instigates bites. At night, Common kraits are very active and escape by hissing loudly or keeping still, occasionally biting the source of the annoyance. When agitated, they will coil up with their head concealed and body flattened, and make jerky movements. They may also lift their tail. Common kraits are reluctant to bite, but when they do, they typically hold on for a while, which enables them to inject considerable amounts of venom. These snakes may become aggressive at night if threatened since this is their active time. They are responsible for 2nd most snake bites in India.
The Common krait's venom consists mostly of powerful neurotoxins, which induce muscle paralysis. The estimated lethal dose for humans is 2-3 mg. Kraits are nocturnal, so seldom encounter humans during daylight; incidents occur mainly at night. Frequently, little or no pain occurs from its bite, which can provide false reassurance to the victim. Typically, victims complain of severe abdominal cramps, accompanied by a progressive paralysis. If death occurs, it takes place about 4-8 hours after the krait bite. The cause of death is general respiratory failure, i.e. suffocation. Often during the rainy season, the snakes come out of their hiding places and find refuge inside dry houses. If bitten by a krait while sleeping, a victim may not realize as having been bitten, as the bite feels like that of an ant or mosquito. The victim may die without waking up. Krait bites are significant for eliciting minimal amounts of local inflammation/swelling. This may help in species identification if the snake has not been seen. The few symptoms of the bite include tightening of the facial muscles within 1-2 hours of the bite and the inability of the bite victim to see or talk, and if left untreated, the patient may die from respiratory paralysis within 4-5 hours. A clinical toxicology study reports an untreated mortality rate of 70-80%. In Bangladesh, more than 50% of total snake bite deaths are caused by the Common krait.
Common kraits are carnivores feeding primarily on other snakes, including: "blind worms" and other kraits, including the young. They also feed on small mammals, lizards, and frogs. The young are known to eat arthropods.
Common kraits are oviparous snakes. Females lay up to 12-14 eggs and guard their clutches until the young hatch.
