The cobra is widely known as one of the most venomous snakes on Earth. Though the shy reptile seldom attacks humans, a single bite from the snake is often lethal. Most cobras can be found in dry regions of Southeast Asia, Europe, Australia, and India. The venomous snakes are also known as the only snakes in the world who build nests for their eggs.
Cobra snakes are members of the elapidae family. Over 100 types of this snake exist. The most aggressive type, the king cobra, contains enough venom in a single bite to kill an elephant, or 20 people. Cobras may grow up to 13 feet (4 meters) in length, and can weigh up to 20 pounds (9 kilograms).
Snakes in the cobra family are distinguished by their hoods, or rib extensions, that extend behind their eyes. These hoods flare out when the snake hisses and becomes irritable or angry. The markings and coloration of the cobra vary by species. Some, like the spectacled cobra, feature eyeglass-shaped patterns, while others, like the king cobra, have stripes. Most cobras are brown, olive, or yellow, and may feature black or white spots.
Members of this snake family may live up to 20 years in the wild. Once grown, the only species that threaten the snake are humans and the mongoose. Nearly any small animal can be eaten by these types of snakes. Most cobras prefer to eat small rodents and birds. Eggs, fish, and lizards may be a part of their diet as well. King cobras in particular enjoy eating other snakes.
King cobras are known for fiercely protecting their eggs during incubation, which usually lasts two and one-half months. Though both parents guard the nest, mother cobras in particular often refuse to leave the next unguarded until the young snakes hatch. A typical nest will contain 20 to 40 eggs. Hatchlings are typically 20 inches (50 centimeters) in length, and are born with full-strength venom.
Though many people fear these types of snakes, the predators can actually be helpful to humans. Like many other snakes, cobras eat pests, such as rodents and other snakes, that typically bother humans. Cobra venom is also used in some medications, such as pain relievers. Though king cobras are well-known for their use by snake charmers of Southern Asia, the snakes cannot hear the music itself. Instead, the snakes respond to the movement and vibrations of the flute.