I’ve always been curious to what exactly this means. I may be overthinking it but like what does this refer to? Does this mean that they have can inject venom up to X amount of people before they die or run out?
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Basically it means that it would take a minimum of X amount of venom to kill the object. The amount of venom delivered is Y times X, with Y being the number of the objects stated. For example let’s say it takes a minimum of 5 milligrams of spider venom to kill a horse, and when the spider bites it delivers 20 mg of venom. So it delivers enough venom to kill 4 horses. (Numbers and units made up on the spot for illustrative purposes only)
There’s a few things to clarify here.
First off there is the concept of “LD50,” (Lethal Dose 50%) which is the dose of something that statistically has a 50% chance of killing any randomly selected person.
Each animal will only store a limited amount of poison/venom in their body at any given time, though they will replace this as it’s consumed.
So, if you take the amount of poison or venom present in a single animal, divide that by the LD50, and then divide that by two (since half will survive the LD50), you end up with an estimate of how many people could hypothetically be killed by thr quantity of poison/venom in the animal.
Every chemical has a lethal dose, the minimum amount needed to kill a particular organism. If an organism ingests less than this amount, chances are that they will live.
So when we measure the volume of venom injected per bite, and compare this to the venom’s lethal dose, simple math tells us how many people this particular volume of venom could kill if the venom were to be split up evenly into lethal doses and admimistered one dose per person.
Generally that just means that their venom glands hold enough venom in reserve to kill that many people, at any given moment. In other words if 10mg of the venom is lethal, and they hold 1g of venom then that animal is said to be able to kill 100 people based on the volume and potency of the venom. In practice few animals would be able to deliver 100 fatal bites/stings.
I’d add that in general this number is arrived at based on the dose it takes to kill half of a cohort of lab animals, usually mice or rats, called the LD50.
Venom potency is normally measured as [an LD50 – the amount of venom mass per body mass that needs to be injected to cause 50% mortality](https://en.wikipedia.org/wiki/Median_lethal_dose).
When people say “enough venom to kill X people”, they likely mean that the animal’s venom glands contain a reservoir of venom with enough mass to give X average people a dose that large or larger.
Injecting that many people isn’t really realistic for most venomous animals, which typically seek to use their venom for hunting something smaller than humans or as a last resort defensive weapon.
it’s volume before their venom sacs are depleted. Cobras for instance don’t have the most toxic venom but they pack a ton of it. That’s why it’s said they can kill 20 people or an elephant.
Lets say you had a syringe full of venom, and someone said that that amount could kill 100 people.
That means that that amount is 100x the amount required to kill one person. So if you took that syringe and divided it equally between 100 syringes, each one could kill one (average) person.
Most chemicals have an LD50 value which is what people usually mean when they say it is enough to kill you. This is the amount of chemical weight per victim weight that is necessary to kill the victim 50% of the time (this is usually specified for a rat or mouse since most people consider running this experiment on humans to be unethical.
Using statistics, we can determine the average weight of a human, and how much venom the animal injects per bite. We can then do a calculation to determine how many people they could kill.
For example:
The inland taipan (a particularly dangerous snake) has a venom with an LD50 of 0.025mg/kg (NOTE: this is for subcutaneous injection). The average inland taipan snake injects 44 mg of venom (110 mg being the record). The average adult human (globally) is 62kg.
We have all the information to say how much is required to so many people…
It will take 0.025mg/kg * 62 kg = 1.55 mg to kill 50% of average weight adult humans.
The number of lethal injections from one bite is 44mg / 1.55mg = 29.3. Since this is a 50% lethality rate, we can divide this number by 2 to yield about 15 adult humans per bite (about 50% would survive a 1.55mg injection without medical intervention).
Interestingly, the apparent estimate is 100 adult male humans per bite. I am not sure where they got this estimate, but maybe they have some evidence that the venom is more lethal for humans than it is for mice.
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