Mating season for most snakes begins in mid-spring. Unlike most other creatures, snakes have no rituals or competitions involved in the process of mate selection. When male snakes are ready for reproduction, they approach any other snakes they encounter. They use their tongues to detect pheremones given off by other snakes to determine the sex, species and reproductive readiness of the potential mate. If the other snake is another male, a brief fight generally ensues. If the other snake is a female of the same species and is ready to reproduce, the male will begin the process of mating.
The Reproductive Act
Females are resistant to mating from the beginning and throughout the process. Male snakes must hold females down with their heads and coil their tails around the female's. The female will continuously try to slither off, dragging the male along as he attempts to line up their cloacas. When successfully aligned--an effort that can take anywhere from a few hours to a few days--the male penetrates the female with one of two penises (known as hemipenes), which then engorges to prevent being shaken out. At this point, the female ceases to resist, and both snakes lie still for the duration of the mating, which typically lasts about an hour.
Though snakes are solitary creatures, the male snake will stay with his mate for two or three days after breeding. Often they will mate once or twice more during this time. The male then leaves his partner.
Snakes reproduce in one of two ways. In colder climates, eggs are incubated and hatched internally, with live snakes being born. About one-third of snake species reproduce in this manner, which is known as "ovoviviparous." The other approximately two-thirds of snake species are oviparous, meaning they lay eggs. The female finds a suitable spot after the male departs and generally lays about a dozen eggs, though the amount ranges from two to 50 among different species, with larger quantities coming from larger types of snakes. King cobras are the only snake species that actually build a nest. Eggs are usually left unguarded, requiring no parental incubation. Newborn snakes are fully functioning and are on their own from the time they hatch, having no contact with their parents.