This is a key part of my snakebite mystery story, which I am thinking of making part of a medical mystery series. I have been told that it actually is more life threatening to the snake for it to squeeze it's prey or threat non-lethally if the snake is venomous. I don't see why. It's not like it would be likely to cause the snake to be injured since snakes are extremely flexible.
And it wouldn't affect venom production most likely because a non-lethal squeeze doesn't affect selective pressure for venom. And yes, I know most venomous snakes in real life don't have the muscles to achieve such a squeeze, but that doesn't mean that a fictional snake can't both be venomous and have python-like muscles to achieve the non-lethal squeeze.
Here is what happened at the scene of the snakebite in my story:
The girl stopped to admire the snake.
The snake coiled up around her legs like a python
The snake then hissed and hooded up like a cobra
Her brother took a picture of the scene
The snake struck at her hand
She moved her hand out of the way
The snake struck again, this time at her arm
She couldn't move out of the way in time
The snake fled back into the park and the girl starts bleeding at the bite site
Mom calls the paramedics
Her brother and sister run to school to avoid getting snakebit themselves
Mom stays to watch over the little girl
Paramedics arrive and take her to the STU(snakebite treatment unit) of the nearest hospital
This non-lethal squeeze from a venomous snake is part of what is fueling the suspense of my snakebite mystery story. That along with the unusual symptoms(like blindness from a snakebite, that is pretty much unheard of, but the little girl does go blind) and the competition between scientists and doctors to figure out what is going on and how to cure it.
So, what could cause a venomous snake to squeeze its threat in a non-lethal manner?
I would imagine the squeeze would be to hold on as it climbs up to the perfect strike position. And I would imagine that for big prey(like bigger than average for a similar sized snake), or prey that tend to flee faster than the snake can catch up, it would actually prove beneficial for the snake to squeeze the prey non-lethally first to immobilize it and then strike and envenomate the prey to kill it, and thus would be selected for, not against, as far as evolution is concerned, since it means more food for the snake which means a higher chance of surviving to next breeding season. But that's just my hypothesis.
So, why would a snake that has venom powerful enough to kill a person, squeeze its threat non-lethally before striking and injecting its venom? And importantly, is there anything besides muscle bulk that is required for the snake to be able to immobilize it's prey or threat via squeezing?