26/11/2025
VERY LONG POST
This is my write up of Smiles and Urb breeding which started in Nov 23 - over two years ago. The babies are nearly 18months old. I've documented the journey and this write up will be on our website too. Hopefully it's interesting and useful. Happy to answer any questions.
Breeding season 23/24 - The big write up
The build up - seasonal cycle
The plan was to drop light and heat on Smiles and Urb through October 2023 and then introduce Urb to Smiles early November.
1st Oct 2023: drop lights 10 mins per day (5 mins am and 5 mins pm)
4th Oct: Weights taken; Smiles 10.0kg, Urb 9.3kg. Approx lengths, both around 2.4m
9th Oct: drop lights 10 mins per day. Drop night time temps by 0.5C (leave day time temps)
17th Oct: drop lights by 10 mins per day
20th Oct: Feed - Urb jumbo rat, Smiles medium rabbit (~1.5kg)
29th Oct: drop lights by 10 mins per day. Drop night time temps by 0.5C
9th Nov: Urb shed
The introduction and courting
11th Nov - Freshly shed, Urb was introduced into Smiles’ enclosure.
The introduction went smoothly, both snakes were immediately aware of another snake in the space. Urb took a long time to make his way fully into the enclosure - smelling everything on the way, while Smiles moved only a small way towards Urb. They finally met face to face, Smiles had an initial recoil as they touched, but after that seemed to realise that there was no threat.
Early courting was mostly Urb sitting wherever Smiles was, occasionally trying to line up tails, and often sitting with his head on her back or neck. Other than that, no real mating behaviour was observed.
27th Dec: Urb removed for feeding. During this time, Urb smashed up his viv, pulling down branches, leaving s***m everywhere and I even caught him locked around a stick. He was clearly restless and the cycling (plus introduction to Smiles) had put him in breeding mode.
3rd Jan 2024: Both Urb and Smiles had a jumbo rat (~500g)
15th Jan: Urb returned to Smiles. After a few weeks apart for feeding, Urb was reintroduced to Smiles. There was much less reaction this time and Urb quickly found his space curled up next to Smiles.
The behaviour of courting, continued
10th Feb: There were some potential breeding moments ("locks"), but nothing definitive. I saw a number of attempted locks, which got closer together as time went on. Urb's interest intensified, and on February 10th, his behaviour changed dramatically. He became super active with a noticeably darker coloration. Later, he curled up on his own, away from Smiles - which he hadn’t done all winter. While we didn't witness a lock, these signs suggest breeding might have occurred. Soon after this Urb went into a shed cycle.
21st Feb: Possibly ovulation. It also looked like Smiles went into shed. But I don’t think this was actually the start of her shed.
29th Feb: Possible ovulation and probable start of shed cycle. I noted several dates of possible ovulations over the weeks before (and after) Urb was removed. This one may have been the most likely. Smiles also started sitting on the hot end much more of the time (some days without leaving the hot end).
3rd Mar: Urb shed.
4th Mar: While we didn’t see a lock, Urb was removed - his behaviour had changed and he was no longer as interested in Smiles. The removal was partly due to lack of interest, and partly to feed. If they didn’t need feeding then I may have just left Urb a bit longer.
Pregnancy
8th Mar: light cycle back up 10 mins per day
13th Mar: Smiles shed (13 days after the possible ovulation on 29th, or 21 days after the possible ovulation on the 21st). It’s still very uncertain whether this is a POS or just a natural shed. I treated it as a POS and that led to the due date being 26th June 2024 (105 days from POS).
15th Mar: light cycle back up 10 mins per day
Urb got the easy bit at this stage. He had two quick meals (medium rabbits) and went back to his usual, calm self - although it did take 4-6 weeks. At least he had stopped smashing up his vivarium quite as much
~25th Mar: Smiles fed a jumbo rat. She ate, but without the usual eagerness of Smiles (this was only the second meal she’d had since pre-introduction in Nov).
26th Apr: After being curled up mostly on the hot side since her (presumed) POS, Smile started seeking even more heat - pushing up against the heat bulbs, and resting her chin on them. As such, I turned up the day temps by 0.5C
29th Apr: Smiles was still against the heat bulbs, plus 0,5C.
5th May: Another 0.5C. This one triggered a new routine for Smiles. Rather than spending all of her time at the hot end under the basking spots. Smiles now kept herself mostly at the cool end during the day and night. But each day, somewhere between 11am and 3pm she would move across the viv to bask under the heat. The basking varied a little bit in the start/end time, but usually lasted around 2-3 hours. Then she would head back to the cool end and stay there.
During this time, I was concerned that Smiles wasn’t drinking. Her route to and from the basking spot didn’t take her past her water. So I added a second, smaller water source to the viv, right next to her hot spot basking area. I tried not to leave the water under the heat long, but was able to time it so that I put it in just before Smiles moved over to bask. I still didn’t see her drink from this bowl either, but she did investigate and she knew it was there.
The birth - Approaching day 105 (26th June).
21st Jun: I wasn’t expecting Smiles to be early - the true BCs are a bit bigger and slower than BIs - and Smiles is slower than most. However, this was the first day in ages that she didn’t come to the hot end to bask. I was fairly confident that she was going to give birth at the cool end, and I took this lack of basking to be a sign that it was soon. In hindsight, this coincided with some hot weather, and perhaps the cool end was warmer than usual. After this she went back to her day basking routine.
26th Jun: Smiles was back in her routine and the 26th was no exception.
28th/29th Jun: Overnight into 29th June, Smiles left a waxy stool/plug. This didn’t look exactly like the other examples that Google showed me, but it was clearly different from faeces/urate. Smiles was clearly restless from this point, but this mostly meant changing coil position rather than going up and down the viv.
29th/30th Jun: Nothing on the morning of 30th. I had expected the waxy stool to be a 24 hour mark - but apparently it could still be 4 or 5 days.
Baby Snakes
30th June: BABIES. I returned home from a reptile display around 5pm. Smiles was in her cave on the hot end (not where I expected). There were 3 babies visible and Smiles looked like she might still be having contractions - although we didn’t see whether any more babies were born after this point.
We let Smiles fully finish giving birth - by 8pm there were no obvious contractions and she looked more settled/coiled around the babies.
We managed to remove Smiles - she was a bit defensive, hissed a few times and made it awkward for us to get her out from the cave. She stood off at us a few times, threatening to bite, but other than hiss there were no strikes. With a combination of two snake hooks we managed to get enough of Smiles out so I could reach in and take her. There wasn’t much fight from this point - I suspect that she was really tired. She went straight into a RUB of warm water, and we moved her to a quiet part of the house.
I had set up Smiles’ old vivarium for her - nice clean, soft bedding, and we put Smiles and her bath into the viv. She stayed in the water an hour or so longer before coming out and curling up as far away from the world as possible right at the back of her hide. In the water she left a small defecation and urate, along with some left over birthing fluids (or at least what I assume was left over birthing fluids - it was runnier than urate).
The babies were then removed from the viv. Once Smiles was out, we could see that there were more babies further in the cave. The three that we could see were the ones that were away from the rest and looked a bit dry. The babies were removed as gently as possible - taking any umbilical cords and goo that was still attached - and placed into a rub with damp layers of kitchen paper. There were two babies that were clearly never going to survive - one that looked to have been stillborn, and one that may have had some life but had a very deformed/undeveloped spine. Whether or not it had any life, by the time the other babies had been removed and we went back we could confirm that this one was not alive.
2nd July: Smiles got a medium rabbit. Eaten fairly quickly, and then straight back to the hide.
The babies stayed together on damp paper towels - changed daily (or twice daily, since the cloying protein smell in the humid tub was quite a lot) - on a heat mat with a warm end around 32-33C (very difficult to read an accurate temp, as the babies kept moving the thermometer probes (the thermostat probe was fixed on the outside, so the babies couldn’t move it, and so I knew that kept a good overall temp). Sometimes the thermometer was in the middle of the clump of babies and was reading 35C, sometimes outside reading 28C. It seemed like the babies monitored their own temp by moving themselves around each other.
7th July: Babies all have dull eyes, going into their first shed.
10th July: The babies all shed on the same day, it felt quite quick considering they only went into shed on the 7th. Given that they were all still in the RUB on damp paper towels none of them had any issue shedding - 15 tiny socks. I was expecting them to shed overnight (since a lot of snakes tend to shed overnight, including boas), but they started shedding around midday and the last one had shed by early evening.
As they shed, I moved them out of the RUB and into their own individual accommodation. I had a combination of large rack draws (33l and 24l draws), and assorted small vivaria (mostly 2-3ft). Initially all the housing had paper towels as a substrate. This would allow them to be kept clean and humid and make it easy to monitor f***s and urates. (Later I moved all of the set ups to a substrate of coco coir, orchid bark, and forest moss - which was kept quite damp to make sure humidity was high.) I used a combination of plastic hides, cork bark hides in each - at least 1 of each, and in many cases more hides were available. Other decor was included in all set ups - such as cork branches, river pebbles, bog wood, other drift wood, and plastic plants. Each set up had a small glass water dish.
17th July: all babies got weighed. 14 of the 15 ranged from 104g to 110g. (My holdback weighed 106g). One of the babies weighed 95g (slightly smaller than the others, but not easily noticeable).
17th July: First feeding attempt for all babies. Between their first shed, and the weigh-in, the boas had been left in peace in their new set ups. This was the first time they’d been left without my regular interaction, since when they were in the RUB together, I was cleaning the paper 1-2 times per day.
I left it until the early evening, just as it was getting dark (around 9pm) and the first meal offered was a medium mouse. The mice were warmed up and offered on tongs. Most of them showed interest, but only a few struck the mouse off the tongs. At this point, I was thinking that I might struggle to get them feeding - since none of them had bitten me in all of their daily handling, I thought perhaps they might not have the instinct to strike for food.
I left the food offered in each enclosure where the baby hadn’t struck and coiled. I thought I would check back in the morning and see. If I had some reluctant feeders I would have to think about how to get things going in subsequent feeds.
18th July: Early morning, I went to check all of the babies and which ones had fed…. ALL OF THEM HAD EATEN!!! Amazing. So not only did I have a whole litter that had shown no inclination of biting me, but I also had a full litter that fed on their first attempt!!! I LOVE BOAS.
1st August: Everyone was packed up and we visited Emsworth Reptiles in Drayton. We spent the evening probing the babies. NOTE to anyone doing this - the babies were able to remain tense and made testing males difficult. After the first few were all showing female, we wondered whether a little more pressure on the probe was needed - and yes, it required a bit more pressure to see whether the snakes were male. We then went back to the first few again and re-tested, then found some of them to be male on the second attempt. I’m really glad I had Paul help me - since without his experience I would have had no change. I would have concluded I had 15 females and convinced myself they were parthenogenesis.
When all was said and done, we had 9 males and 6 females.
A couple more feeds (with no issues at all) and the babies were ready to start going to their new homes. The only thing to consider now - which one was going to be my holdback!!!
And that turned out to be 2 holdbacks.
