The breeding of Psammophis sibilans

Ton Steehouder, Geeneinde 4, 2381 Weelde, Belgi. t.steehouder@psammophis.nl



In July / August 2007 the Dutchman Tom Vos acquired five specimens of Psammophis sibilans, imported from Egypt. Two animals did not thrive well from the start. All animals were housed separately.
In order to determine the sex, the animals were all probed. This method is (but the owner did not know that at that time)  not only not reliable for snakes of this genus, but also not safe. This snake belongs to the Psammophiine snakes, that are all characterized by very short (approx. 5 subcaudals length) and thin hemipenes, almost in the form of a thin rain worm. Probing can easily cause serious damage.
One animal was suspected to be a male. This animal was smaller than the others.
When the two weak animals had died, the other three were placed together. During the daythe room temperature was 25.5 C. In addition, they had a spot in the terrarium of 25 Watts. At night the temperature dropped to 23 degrees. The room had its own independent thermostat.
The animals basked for only a few hours each day under the spotlight. The rest of the time they were often hidden under artificial plants and bark. This behaviour is common for the species in captivity.

No mating behaviour was observed. Nevertheless, one female became pregnant in 2009, an animal of about 80 cm long. She eventually laid six eggs, two of which spoiled (though fertilized). Four eggs hatched on July 8, 2009. When Tom took the young snakes from the incubator, he saw two snakes with an "open belly" where the umbilical cord had been detained. He had never seen that, I did in the eighties in two hatchlings. The opening usually closes without problems. One of Tom's hatchlings unfortunately did not survive. Two hatchlings started after a while to feed independently (defrosted) pinkies, the third was force-feeded with mice tails that were pushed into the mouth, after which the snake started to swallow them.

Meanwhile, the supposed male (there were as indicated no pairings observed) deceased around March 2009. Tom found him paralyzed in the terrarium: he could only move his neck and head, and a few inches behind the neck there was a bump. Presumably, it was seized by one of the other snakes. Possibly this is a case wherein a sudden movement of a hunting snake evokes a response from another snake. Another possibility is that one of the other snakes has been a male too and that there has been a dominance combat. Tom had seen nothing of the kind, anyhow. In 2013 I observed (and filmed) fierce fightings between two male descendants of Tom's snakes. For their description, click here.


The two remaining snakes, of which one had laid eggs, were sold to me in January 2010. On February 1 they arrived.
I gambled that the slaughtered animal had indeed been a male, which was slain by the other male in a dominance combat, and that the two remaining animals would be a couple.

In my room the temperature at night dropped to16C. In the eighties and nineties this had always been the case in my snakes rooms,and the breeding had always proceeded smoothly. During the day there was a warm place below and above the spot, where temperature reached more than 25 C. The animals were warming up the day.
The (slightly) larger specimen of the two had nicely patterned supra- and sublabials, the smaller specimen didn't. This larger specimen feeded very well on nestling rats and was getting quite fat early March. I have not seen pairings. However, the animals were several times in a position that might indicate a mating: very quietly lying on each other, with the cloaca of the upper animal (the unpatterned) right above that of the lower (the patterned). Even with a mirror I could not see any hemipenis.

On 22 March 2010 the fat animal sloughed. After this sloughing its volume increased, and from March 24 on the behavior of both animals changed. Before, they had been lying under the spot light quietly. Now they became alert and nervous, and reacted to every move they observed outside the terrarium. At the slightest danger they quickly disappeared into the hiding drawer. It even seemed that they actively warmed up, and then the went into the security of the hiding place. Clearly, attempts to close the access to the drawer had to fail.

Finally, against all odds, I positioned a container with a layer of sand right under the spotlight. For some days both animals went into the container repeatedly, but on March 30 the female disappeared into the hiding drawer, in which she deposited her eggs on March 31 2010, in the coldest but safest place in the vivarium. There were 7 good eggs, with a length of about 38 mm (see picture). One egg was dried and had dark spots. this can be the egg that had been nearest to the cloaca, but I have not been able to check that.
I tried to hatch these eggs in an incubator au bain Marie at 28C, but during the following weeks all eggs spoiled.

On June 12, 2010 there were again 9 eggs, this time layed in a hiding box. I put these eggs in the same incubator, again at 28C. And again most eggs spoiled, leaving only three.
On August 2, 2010, the first snake cut its egg shell, and the next morning it hatched. I had placed the container with the eggs in a small terrarium by now, heated with a heat cable and a small light spot from above.

As usual, the hatchlings refused all food offered. I forcefeeded them every two or three days with tails of mice or rats and with slices of cow heart. After some time they all started to feed on their own, first pieces of nestling mice, then dead incised pinkies and afterward live pinkies.

One animal grew faster than the others. Although there had been no food in the terrarium (which excludes a fight for prey) the largest animal swallowed a smaller sibling, and a couple of months later this was repeated. So there was only one left.
Was this normal? I had not had this kind of nasty experience before with my sand snakes. On the other hand, Gilian reported in a Snake Forum that a female, born in 2009 with Tom Vos, so a sister of my animals, laid eggs (he added some magnificent pictures), and then was killed by another female. He discovered her dead, covered with mucus and sand on the front part of the body, while the offender had sand in her mouth. No prey was present here too.
So, of the offspring one of three killed her sister/brother; and one of my offspring ate two other ones. Could be a family trait. It's even possible that animals from a certain population are more cannibalistic than animals from other populations.
I must add that the same female as an adult never attacked other specimens - until now - and that the trick was not repeated by her offspring and grandchildren.


In 2011, the wildcaught female I bought from Tom Vos, laid again 9 eggs, that spoiled all. A second clutch, laid on June 3, proved better. In the following table you find the data.

Egg nr.

Dimensions in mm

Weight in grams





























If we compare this table with the one I gave in my article about the breeding with P. cf. subtaeniatus, we see that the eggs of this new clutch were more or less of the same length, but were thicker and so in average heavier.
In the first couple of days the eggs grew (about 2 grams in weight) by moisture absorption.

On August 5, 2011, all eggs had hatched. Of the hatchlings, in the end 5 started to feed by themselves (pieces of nestling rats, incised pinky mice). One hatchling only started feeding in June 2012. In that month 7 were left, one of them still refusing all offered food, en becoming thin. I euthanized this animal.
One of the other juveniles was a bad feeder and remained small. I put it in a separate container, and in spring 2013 I put it together with three hatchlings Malpolon insignitus. All four started to feed very well, and the little sibilans grew very well.


There was no breeding in 2012, as I didn't have the breeding animals anymore. I euthanized them in 2011 for medical reasons: first the male, then the female had a hard, oblong swelling just before the cloaca, filled with dried pus. I tried to cure the infection by opening and cleaning it, and injection of antibiotics, but in vain.

(Though I experienced this way that treating a snake that wants to be free and will bite readily, can be made quite easy by using the non-sticking tape that comes in a variety of colours as bandage for broken arms, fingers etc. I tok a piece and wound it around the head of the snake, to immobilize the jaws. Afterwards, it can very easily be removed.)

As it was clear that the infection was contagious, I took no risk and euthanized both animals, to prevend the infection spreading to other animals in my collection.
After all, it was not that important that I should breed a lot of them, as almost nobody wants them. And there were still 6 left.


On March 8, 2013 I observed a mating between two animals born in 2011. See the picture below.


On April 4 a young female, born in 2011, laid 4 beautiful eggs, that I put in the incubator in the usual way: au bain Marie, in and half covered by moist sand, at a temperature of ca. 29C. 

Another young that had been growing less and was therefore put apart, first in a small container, later together with three young Malpolon insignitus, appeared to be courting one of the insignitus (a young male).

On the evening of April 13 I put the two largest sibilans from the group of 2011in a new terrarium, where they were combined with the large animal that was left over from the breeding of 2010, after it had eaten its siblings.
The next day it is clear that this large 2010 animal is a female. She is heavily courted by both the animals of 2011, both males, apparently.

The next morning around 08.00 h. the three larger sibilans are mating, lying very still as usual. Both males tried, one succeeds. Mating continues until at least 09.30 (last observation). Around 10.30 they are crawling through around again. Courting goes on all day long until the lights are down. I made various photographs and videos. One video take shows a mating that continued for at least 27 minutes.

In the other terrarium are the remaining sibilans from 2011, one of them the small female that laid the eggs on April 4. There is mating behavior too, which is not astonishing as in this group there is the young animal that tried to mate with a Malpolon.

The conclusion is, that at that moment I have two terrariums, each with at least one female and at least two males.

May 2013

The female born in 2010 sloughed on May 4. She was heavy, and the eggs were visible in her body. After the shedding there was also almost permanent mating activity, with a succesful mating on May 7.
On May 8 the female laid eight eggs, at first sight viable, with slightly differing dimensions (see the photographs). They were put in an incubator aside of the eggs of the younger female of April 4, that had clearly been growing and were now much bigger than the new ones.
It goes without saying that all eggs were not deposited in the box I put in the terrarium, but under it. See the photograph.


Within an hour after the last egg was laid, there were new matings, and again after an hour the female accepted a small mouse.

What is remarkable, is that the female in question was combined with the males only three weeks before the eggs were laid, namely on April 13. This female had never before been in the presence of a male. Of the eggs she laid on 8 May, three spoiled after some weeks, but on June 29 another one hatched.
That means that these eggs were indeed fertilized and viable, in spite of the very short period between fertilization and laying (a bit more than three weeks).

The same day the female accepted a little mouse, and the next day a lot more. Mating continued in the week to follow.


On May 16 around 18.00h I witnessed something I had seen before, but never as long and intense: a violent (but undamaging) dominance fight between the two men that were together with the big female from 2010. The large female had just shed and was basking. Both men were engaged in a fierce batlle that caused a lot of noise as they threw themselves or the other against the walls and logs. I filmed a part of this fight. The remarkable thing was that they did NOT bite each other. Notwithstanding that, I think that the male that died with Tom Vos (see the intro of this article) did so as a result of this kind of fighting.
When I really had to leave after an hour or so, and noticed that the intensity of the fight increased instead of diminished, I put out the light, whereafter the unrest decreased as planned and in the end the animals became quiet.

The following video shows only a part of the fight. I have more material, but did not publish all of it. Who would be interested, after all?

Hatching in 2013 (1)

On May 24, 2013, three eggs form the first clutch (F2011) had spoiled, but the 4th showed a slit in the evening of May 24. Next morning a little head peeped out. This means 50 days of incubation at about 28C, which is rather short.


After a week the little snake sloughed and I could start the usual routine of force-feeding with mouse tails.

More clutches (1)

June 13, 2013

In the morning of June 13 I found the oldest female (F2010), that had eggs on May 8, wound again around 10 eggs in the corner of the terrarium. I removed five eggs, leaving the other five to see how far the care of the mother would go. Well, not very far. After some hours she left the eggs and never returned. I then put them in the incubator too, along with the other five.

Hatching in 2013 (2)

June 29, 2013

During the incubation periode three eggs from the clutch of 8 eggs laid on May 8 (F2010) spoiled, two only about two weeks before the presumed day of hatching. A fourth egg hatched on June 29, the others in the days thereafter. All are stout and healthy. Mind, that these were the eggs that can only be fertilized by a mating only three weeks before hatching.

More clutches (2)

September 8, 2013

On that day I find in the terrarium, under a heap of plastic plants, a half dried clutch of nine eggs. All eggs are clean and white, though crinkled. I experienced this before, in 1994. All eggs had then already hatched, but all hatchlings were gone, except one: a dead young, that was hanging damaged and dead in the branches, obviously a victim of the other, adult inhabitants of the terrarium.


Assuming that these new eggs will also hatch normally, I put the clutch in a container filled with moist sand, but not in an incubator but simply in an empty terrarium, with exactly the same conditions as when they had been left in the same spot. These eggs are by the way significantly smaller than those of the adult female, laid on June 13.
On September 17 I found still another egg, apparently escaped from my attention. It was empty, already hatched, the hatchling disappeared. History repeated. It implies that the eggs must have been laid in the middle of July, about a month after the clutch of the large female. It also implies that the 2010 female has laid four clutches, with intervals of about a month: first 8 eggs, then three times 10 eggs. They were not all equally succesful:

Tabel: eggs of the F1 female from 2010, laid in 2013

Date Number Hatched Number of live hatchlings
8 May 8 from 29 June on 5
13 June 10 from 26 July on 3
ca. 15 July (dry clutch) 10 from September 8 on until September 25 10
22 August 10 from 18 October on  

On September 25 all eggs of the dried clutch of the middle of July had hatched. Including the lost hatchling that means hundred percent succesful result, exactly like in 1994. This season, the results have even been better for the eggs outside the incubator. The duration of the proces did however vary stronger than when the eggs were put in an incubator with constant temperature.

The juveniles of 2013

The eldest juvenile (from the clutch of the 2011 female) started to feed on its own rather soon and grew fast. Of the other clutches, a growing number of juveniles started to feed.

When young, they seem a little less nervous and flighty than the older animals. In older animals, a lot seems to depend on temperature. When they are hot, your hands had better stay out of the terrarium. For any reason they start flashing through the enclosure, and react to anything that is observed in front of the glass panels. Sometimes it is not easy to get food in. The first juvenile of the year 2013 is growing very fast, and catches the prey before it even has a chance to touch the ground. If I would stick my finger in the terrarium, it would be caught as if prey.

Hatching speed

From the clutch of 22 August 2013 the first hatchling emerged on 19 October, the last on 23 October. The time between first emerging and complete hatching is given in the following table.

  Time between first emerging and hatching
1 ca. 12 uur
2 between 3 and 11 hours
3 between 1 and 8 hours
4 ca. 7,5 hours
5 between 6 and 8 hours
6 between 8 and 10 hours
7 at least 7 hours
8 at least 10 hours. Weight: 7 grams
9 between  4 and 12 hours. Weight: 6 grams (largest egg)


The first mating I noticed was on March 23: the oldest female (2010) and one of her males. Mating continued the following days.

F2 female: April 2, 6 eggs
I buried these half in moist sand in a plastic container, and put the container in the terrarium. Temperatures sunk to a minimum of 18C during the night, and slowly rose to a maximum of 28C by day. Under these circumstances, all the eggs gradually dried, and did not look very well in the end. Two of them dried and discoloured, the others remained white. The picture below shows the eggs after some weeks. The eggs below are the spoiled eggs.

On June 16, one egg hatched, with a healthy looking hatchling as a result. There was no moist residue left in the egg, and the egg was slit open in one of the 'points'. The next hatchling came on June 21, in exactly the same way., and the third on June 24, though this one through a slit in the middle of the egg.

The incubation duration was 75-80 days at a fluctuating temperature between 18C and 28C. As could be expected, this is longer than at a constant temperature of 28C. By comparison: in 2013 two clutches hatched after 52 and 57 days.

In this experimental clutch, 50% hatched, three out of six. Less than in 1994 when the eggs were overlooked and were left in the terrarium and all hatched, and also less than the clutch of 2013 that was left in the terrarium for some weeks, were dried out but were put in moist sand after that. These eggs all hatched.
On the other hand, from clutches that were very much cared for with ample moisture, some also did not hatch completely, in one case (cf. 2013) even only 30%.  It is not at all clear why some eggs do not develop well, and others do, in exactly the same circumstances.
Another thought could be that there was a difference: in 2013 the eggs had been dry during the larger part of their incubation, and only buried in moist sand in the last period. In 2014 the eggs were buried in moist sand in the first period, then gradually dried. I have no idea what the influence of this difference can be.

The three hatchlings were put in a terrarium and appeared well.

F1 female: May 18, 9 eggs.
These eggs were buried in moist sand and put in an incubator at 28C. They all remained healthy. When in the end days of the incubation the sand became too dry and the eggs started to crinkle a little, I added water by simply pouring some over the eggs.
On July 143-14 the first one hatched during the night. It was slightly heavier than the hatchlings of the cluster F2 of April 6, that had heavily dried out. The weight of 7 grams was normal, as I was used to for most of the hatchlings I had in the past, though somewhat smaller than the first hatchling I had from the wild caught female in 2010 (that were 9 and 10 grams). The next day, two others hatched, of the same weight. The last two (July 17)were the heaviest: 8 grams and 9 grams.

F1 female: around July 4, 9 eggs.
In the morning of July 9, 2014, I found 9 eggs of the same female. That means: about 47 days after the last clutch was laid, somewhat more than in 2013 between the clutches, but still impressive.
The eggs had been lying in the terrarium for about 5 days, and some of them were slightly crinkled. I put all the eggs in moist sand and placed the container in an empty terrarium, as there was no room in my incubator.
These eggs were smonwhat smaller than those of the preceding clutch.
Incubation temperature varied between 20 and 30 degrees Celsius, dependant on time of day, with consequently a mean average of 25C. A long incubation period could be expected.
4 eggs spoiled during the process, the rest hatched as showed in the following table.

  deposit date date of hatching incubation duration in days weight in grams
1 July 4 Sept. 19 76 6-7
2 July 4 Sept. 21 78 6-7
3 July 4 Sept. 23 80 6-7
4 July 4 Sept. 24 81 6-7
5 July 4 Sept. 26 83 6-7

All hatchlings weighed between 6 and 7 grams, and appeared healthy and viable.


From the end of February on, light duration and temperature were raised, along with normal light cyclus in Belgium. On March 24 I noticed the first mating by the oldest couple (female 1, cb 2010, male 1, cb 2011). On April 6 I filmed the mating (see film 68).

Pictures of mating Psammophis sibilans in 2015

The second couple was kept in an other cage, with lower temperatures during the night but also by day. These animals were reluctant to leave their place high in the cage on branches to seek heat on the heating mat or under a spot. They did not accept food either. Only from March 25 on I saw them more actively seeking heat. I observed no mating behaviour.
Yet, this female laid 6 eggs in the early morning of 26 April 2015. Average weight of the eggs: 1,67 grams, average dimension: 39x18,3mm.

Table: eggs of Psammophis sibilans, female 2, 26 April 2015

nr dimension in mm initial weight (gr., 1)    
1 39x20 10    
2 39x20 11    
3 40x20 11    
4 39x15 10    
5 38x20 11    
6 39x15 11    

The eggs were as usual slightly burrowed in moist sand, and incubated au bain Marie at 28C.



Experimental design for 2015

Eggs buried in moist sand at 28C (reference group): all the eggs of the first clutch (6)

Eggs buried in moist sand at 25C

Eggs buried in moist sand at variable temperatures