King cobras follow a pheromone trail to find females. When the male finds the female they follow a set mating ritual where the female flashes her hood at the male and then wraps her coils over her head. King cobras reach sexual maturity at the age of 4 years and breed once a year from January through April. Males lose their appetites during mating season.
After mating, female king cobras build a nest by pushing leaves and branches together into a pile. The king cobra is the only snake that is known to build a nest. In the nest the female lays 18 to 40 eggs, which are kept warm by the decomposition of the sticks and leaves used to build the nest. The female sits on top of the nest. During this period, cobras are particularly aggressive towards humans. The eggs incubate for 70 to 77 days, which means that the parents guard the nest throughout the spring and summer, and the eggs finally hatch in fall.
When the young cobras hatch, they vary in length from 12 to 25 inches. At birth their venom is just as strong as an adult's venom, which means that they do not need adult protection.