Kraits are strictly nocturnal and follow prey into buildings, particularly during monsoon rains that flood their ordinary shelters. A large share of documented bites occur indoors between roughly midnight and dawn to people sleeping on floors or low bedding.
The clinical difficulty is that a krait bite may produce minimal local pain, little swelling and fang marks that are hard to find. Its venom is a presynaptic neurotoxin that blocks the release of acetylcholine at the nerve terminal, and the effect develops over hours: abdominal pain, drooping eyelids, difficulty swallowing and eventually respiratory paralysis.
Because the onset is delayed and the local signs are faint, cases have been misdiagnosed as gastroenteritis or stroke, and the underlying bite is sometimes never identified. Antivenom is less effective once the presynaptic block is established, which is why ventilatory support matters so much. Reliable national bite counts remain hard to obtain, as many deaths occur outside hospitals.