People often suspect that they have a snake nest in their garden or in the roof of their house. What are the chances of that being true? Johan Marais explodes the myth
The king cobra, to the best of my knowledge, is the only snake that has a “nest”. It will even drag a few branches closer to its body to build a crude nest in which to lay its eggs. But none of the African snakes do that. They do not have nests.
Female snakes heavy with eggs will select a suitable spot to lay them, and it will usually be down a hole, under a rock or in a hollow tree trunk. She has to find a spot where the eggs will not dry out as they are soft and leathery and require quite a bit of humidity throughout incubation.
The chosen place must be safe from a variety of predators, including mongooses, monitor lizards, various birds and ants.
Some eggs, like those of the spotted skaapsteker (Psammophylax rhombeatus), hatch within a few weeks but others, like python eggs, may take up to three months.
Prior to egg laying, females usually shed their skins and before doing so, the eyes become a blue milky colour. Soon after shedding, the female deposits her eggs in a clump and the eggs often stick to one another. Most females will deposit their eggs and move off without showing any further interest in them. When the eggs are about to hatch, the young within the egg have an egg tooth on the nose or upper lip which they use to slice the egg from the inside.
Not all females abandon their eggs. The southern African python (Python natalensis) and the spotted skaapsteker are well-known for remaining with their eggs throughout incubation. The speckled shield cobra (Aspidelaps scutatus scutatus) reportedly does the same.
The southern African python prefers to lay her eggs in an aardvark hole and may return to the same hole year after year. She will lay her eggs – between 30 and 60 but as many as 100 — within hours and will then coil around them.
The eggs are roughly the size of a tennis ball and will take in the region of three months to hatch. During that period the female goes very dark in colour and will not eat, but might occasionally drink water. During the day, she will bask at the entrance of the hole and quickly disappear down the hole if disturbed.
Most reptiles die if their body heat rises above 42C. Pythons will bask in the sun until their temperature reaches in the region of 40C, at which stage the female disappears down her hole to coil around the eggs and use her body heat to assist with incubation.
In crocodiles, tortoises and many lizards, the sex of the young is determined by incubation temperature. Nile crocodile eggs incubated at 31C produce males whereas eggs incubated at 29C produce females. But this is not the case in snakes.
When the pythons hatch from their eggs, the young tend to hang around the hole for a few weeks and will spend much of their time basking in the sun but will quickly escape back down the hole if disturbed. They then crawl into the coils of the female. But once they move on, there is no further parental care and the female does not help them hunt for food.
Many of our snakes, including adders except the night adders (Causus rhombeatus), the mole snake (Pseudaspis cana), the rinkhals (Hemachatus haemachatus) and the slug eaters of the genus Duberria, all produce live young.
If a female snake does produce her batch in your garden, or some eggs hatch there, you may well have several young snakes in the area that easily create the illusion of a snake nest.