Candle before you cut!

I candle for a variety of reasons - when eggs are first laid, I candle each one to confirm the presence of a viable embryo - this means that eggs which have no chance of success aren't placed into the incubator tub where they would become a reservoir of bacteria. The incubator is an excellent place for bacteria to thrive. Watch the video linked at the bottom for some examples of good and bad eggs. 

Candling eggs later in the incubation process is really cool - you can see the snake coiled up inside the egg, like in this photo. 

One of the most important reasons for candling is to visualise the shell membrane veins, these vessels carry a lot of blood. As the snake embryo grows, the veins grow too - they provide the embryo with oxygen while it develops.

As the snake prepares for hatching, the membrane veins recede, reducing the oxygen that's available for the snake. This is one of the triggers for the snake to cut through the shell and start to breathe air. 

When candling at this late stage, if I see a completely clear top section of the egg, like this photo, with no veins visible, I make a cut. Sometimes I'll sit and watch for a while, and get to see the snake pip on their own, but if there's any sign of struggle at this stage, I'd rather make the cut.

The generally accepted 'rule of thumb' when I started out with hognose was that un-pipped eggs should be cut 24 hours after the first egg in the clutch has pipped. I've always candled eggs, and so I would cut at 24 hrs and just try to avoid the veins. I prefer to let the eggs remain intact until the membrane vessels have receded now.

 This photo is from the first clutch of 2025 - all the other eggs have fully hatched, with the first pip over 75 hours before. Cutting this egg without candling first at 24, 48, or even 75 hours after the first pip could result in significant bleeding if that large vein were cut. 

The shell membrane has no nerve endings, and this causes the snake no pain, but for a hatchling at less than 10g, any amount of blood loss is harmful. 

 If the snake isn't able to successfully cut through the shell after the veins recede, they will eventually suffocate inside the egg.  Snakes have a higher tolerance for low oxygen and high carbon dioxide than mammals, but there are limits.

Cutting eggs can save hatchlings, but it has to be done at the right time, and that time is different for each egg, even more so if the incubation conditions haven't been stable.   

Last year (2024 season), I candled the last egg in the clutch to pip and saw that it was clear of veins. I cut the egg and did the 'poke test', but the snake was unresponsive. I had last candled just a few hours prior and had seen movement, I could also see that the snake had attempted to cut through the shell but had only made some scratches. Knowing that snakes can tolerate extended periods of low oxygen levels, I decided to attempt resuscitation. This is a still from the hatch-cam video.

 I massaged the snake's body along the first 1/3 where the heart and lungs are situated. After 5 minutes I could see a heartbeat, and at 40 minutes he started to show signs of voluntary movement and tongue flicks. I couldn't believe it had actually worked!

This is CPR now, a beautiful, extreme red albino that almost didn't make it.