The female king cobra is the only snake species to build a nest for her eggs. In the Western Ghats of South India, a female starts constructing her nest in the dry month of April, just before the rains arrive in May.
She chooses a well-drained spot, often below a large tree or a clump of bamboo. She then spends several days gathering leaves into a pile, sweeping them together with her body, and carrying them in a tight coil – a huge feat which requires enormous amounts of energy.
When she has enough leaves, she begins compacting the pile into a waterproof chamber by repeatedly crawling over it (a completed nest stands nearly a metre high). She then burrows into the heap to create a cup-like hollow deep within, in which she lays a clutch of anywhere between 15 and 50 leathery eggs.
Female king cobras often stay on their nests for the entire incubation period of 75–100 days, their mere presence offering excellent protection.