All kraits are nocturnal. The snake is more docile during the daylight hours, becoming more aggressive during the night. However, they are rather timid and will often hide their heads within their coiled bodies for protection. When in this posture, they will sometimes whip their tail around as a type of distraction.
Fortunately, since kraits are nocturnal they seldom encounter humans during daylight hours so bites are rare. Nonetheless, any bite from a krait is potentially life-threatening and must therefore be regarded as a medical emergency. Note that there is frequently little or no pain at the site of a krait bite and this can provide false reassurance to the victim. Typically, victims start to complain later of severe abdominal cramps accompanied by progressive muscular paralysis, frequently starting with ptosis. As there are no local symptoms, a patient should be carefully observed for tell-tale signs of paralysis (e.g. the onset of ptosis, diplopia and dysphagia) and treated urgently with antivenom. Before antivenom was developed, there was an 85% mortality rate among bite victims.
Krait antivenom is often ineffective for species in the genus other than the snake originally included in the antivenom preparation. Often noted on lay websites is the statement that there is a mortality rate of 50% even with treatment , but there is no original source in the medical literature for this statement. Mortality remains high given that many patients envenomated never make it to healthcare facilities due to the distance from their rural homes and the often profound lack of medical resources, especially intubation supplies and mechanical ventilators in rural hospitals. Definitive care may also be delayed as patients may first visit the local mantrik or tantrik, a holy person and traditional healer who may attempt to rid the body of the venom with spells or herbal remedies, which are ineffective interventions.
Once at a healthcare facility such support should be provided until the venom is metabolised and the victim can breathe unaided especially if there is no species-specific antivenom available. Given that the toxins alter acetylcholine transmission which causes the paralysis, some patients have been successfully treated with cholinesterase inhibitors such as physostigmine or neostigmine, but success is variable and may be species dependent as well. If death occurs it typically takes place approximately 6 to 12 hours after the krait bite, but can be significantly delayed. Cause of death is often respiratory failure ie suffocation via complete paralysis of the diaphragm. Even if patients make it to a hospital subsequent permanent coma and even brain death from hypoxia may occur given potentially long transport times to get medical care.
In 2001, herpetologist Dr. Joe Slowinski was bitten by a juvenile krait (B. multicinctus) while doing field research in Myanmar. He was unable to reach medical assistance and subsequently died from the effects of the bite.
|Species||Authority||Subsp.*||Common name||Geographic range|
|B. andamanensis||Biswas & Sanyal, 1978||0||South Andaman krait||India (Andaman Island)|
|B. bungaroides||Cantor, 1839||0||Northeastern hill krait||Myanmar, India (Assam, Cachar, Sikkim), Nepal, Vietnam|
|B. caeruleus||Schneider, 1801||0||Indian krait||Afghanistan, Pakistan, India (Maharashtra, Karnataka, Sri Lanka, Bangladesh, Nepal|
|B. candidus||Linnaeus, 1758||0||Malayan krait, Blue krait||Cambodia, Indonesia (Java, Sumatra, Bali, Sulawesi), Malaysia (Malaya), Singapore, Thailand, Vietnam|
|B. ceylonicus||Günther, 1864||1||Ceylon krait||Sri Lanka|
|B. fasciatus||Schneider, 1801||0||Banded krait||Bangladesh, Brunei, Myanmar, Cambodia, south China (incl. Hong Kong, Hainan), north-east India, Bhutan, Nepal, Indonesia (Sumatra, Java, Borneo), Laos, Macau; Malaysia (Malaya and East Malaysia), Singapore, Thailand, Vietnam|
|B. flaviceps||Reinhardt, 1843||1||Red-headed krait||South Thailand, South Myanmar, Cambodia, Vietnam, Malaysian Peninsula, Pulau Tioman, Indonesia (Bangka, Sumatra, Java, Billiton, Borneo)|
|B. lividus||Cantor, 1839||0||Lesser black krait||India, Bangladesh, Nepal|
|B. magnimaculatus||Wall and Evans, 1901||0||Burmese krait||Myanmar|
|B. multicinctus||Blyth, 1861||1||Many-banded Krait||Taiwan, south China (incl. Hong Kong, Hainan), Myanmar, Laos, north Vietnam, Thailand|
|B. niger||Wall, 1908||0||Black krait||India (Assam, Sikkim), Nepal, Bangladesh, Bhutan|
|B. sindanus||Boulenger, 1897||2||Sind krait||South-east Pakistan, India|
Roald Dahl uses the krait as a device in his short story "Poison." The krait also appears in Frederick Forsyth's short story "There Are No Snakes in Ireland" (referencing Kipling's Rikki-Tiki-Tavi, with the assumption that Kipling may actually have meant the Saw-scaled viper; included in his collection No Comebacks).
It has also been argued that the deadly snake in the Sherlock Holmes story The Adventure of the Speckled Band may have been a krait, although it is described in that work as an "Indian swamp adder." (The Russell's Viper has also been considered as a possible culprit.)
In a slightly more oblique reference, the motion picture Snakes on a Plane features a villainous snake smuggler named "Kraitler."
In Dean Koontz's "The Good Guy", the hitman assigned to murder one of the protagonists calls himself Krait.
In Guild Wars Eye Of the North there is a race of snake-like creatures called Krait.
In Mercedes Lackey's "The Serpent's Shadow", Maya's father was killed by a krait while living in India.
In the Star Wars: Legacy comic book series, the leader of the New Sith Order is known as Darth Krayt. Though named after the fictional Krayt Dragon, it is possible that the venomous dragon was named after the krait.