Spider mouthparts are adapted to
envenom very small prey; they are not well-adapted to attacking large mammals such as humans. Some experts believe that various spiders like
Phoneutria can deliver a
"dry" bite to purposely conserve their venom, as opposed to a more primitive spider like
Atrax that usually delivers a full load.[
citation needed] A study in March 2009 suggests that
Phoneutria inject venom in approximately one-third of their bites, and only a small quantity in one-third of those cases.
Another study similarly suggested that only 2.3 percent of bites (mainly in children) were serious enough to require antivenom.[16]
Despite their reputation as the world's deadliest spiders,
[2] there are multiple studies that call into question their capacity for fatal human envenomation, though some of these are labeled with a level of uncertainty, as
Phoneutria are often confused with other genera of
ctenids,
lycosids or other large
labidognatha spiders. Of the eight described species,
P. nigriventer and
P. fera most frequently receive mention in mass-media publications.
P. nigriventer is the species responsible for most cases of venom intoxication in Brazil because it is commonly found in highly populated areas of southeastern
Brazil, such as the states of
São Paulo,
Minas Gerais,
Rio de Janeiro and
Espírito Santo. The species
P. fera is native to the northern portion of South America in the
Amazon of Brazil,
Venezuela,
Ecuador,
Peru and the
Guyanas.
And I've talked to some people who have decent knowledge about spiders and scorpions. They aren't as deadly as people make them out to be because their venom is localised; it only affects and spreads slowly on the area of the bite. In the case that antivenom is needed, you actually have a lot more time than you would expect to get it sorted. And most cases, people just get ill for a while and recover back to normal completely.
The seriousness of the case also depends strongly on where the bite occurred. The most likely bites are on the limbs, where people put their feet in boots/shoes or try to reach out to some dark areas of their house with their hands. These cases, since the bite is way too far away from any organs or other important parts of the body, is almost, if not completely, an impossibility to be fatal. It will be very painful and uncomfortable, but far from life threatening.
Where deaths can occur is with small children (because, well, they're small) and when the bite occurs on important areas, namely the chest where the heart is or on the head. Both cases are very, very unlikely to happen. There was a documentary I watched before about a woman militant getting stung by the third most venomous scorpion in Afghanistan. It was a race before brain damage and death could occur, but eventually they got the antivenom to her and all was well.
This is another well-known spider (especially in Australia) that I have got information about (since I had to deal with them while living in the United Arab Emirates):
The redback is one of the few spider species that can be seriously harmful to humans, and its preferred habitat has led it to being responsible for the large majority of serious
spider bites in Australia. Predominantly
neurotoxic to vertebrates, the venom gives rise to the syndrome of
latrodectism in humans; this starts with pain around the bite site, which typically becomes severe and progresses up the bitten limb and persists for over 24 hours. Sweating in localised patches of skin occasionally occurs and is highly indicative of latrodectism. Generalised symptoms of nausea, vomiting, headache, and agitation may also occur and indicate severe poisoning.
An antivenom has been available since 1956, and there have been no deaths directly due to redback bites since its introduction.
The very last part of that paragraph is key. Now, why am I saying all of this? It's mainly because people develop a fear of spiders because of their danger, when there are far more fatal lurkers that definitely can kill. These are, of course, snakes. This example I will post is not the most venomous, but one of the 'Big four' in India which bites; the Common Krait
Kraits are
nocturnal, so seldom encounter humans during daylight hours; incidents occur mainly at night. Frequently, little or no pain occurs from a krait bite, and this can provide false reassurance to the victim. Typically, victims complain of severe abdominal cramps, accompanied by progressive paralysis. Once bitten, the absorption of the venom into the victim can be considerably delayed by applying a pressure bandage to the bite site (using about the same tension as one uses for a sprained ankle) and immobilising the area. This allows for gentle transport to medical facilities, where the venom can be treated when the bandage is removed. As no local symptoms present, a patient should be carefully observed for signs of paralysis (e.g., the onset of
ptosis) and treated urgently with
antivenom.
It is also possible to support bite victims by
mechanical ventilation, using equipment of the type generally available at hospitals. Such support should be provided until the venom is metabolised and the victim can breathe unaided. If death occurs, it takes place about four to eight hours after the krait bite. Cause of death is general
respiratory failure, i.e.
suffocation.
[7]
Often during the rainy season, the snakes come out of their hiding places and find refuge inside dry houses. If bitten by a krait while sleeping, a victim may not realize he has been bitten, as the bite feels like of an ant or mosquito. The victim may die without waking up. Krait bites are significant for eliciting minimal amounts of local inflammation/swelling. This may help in species identification if the snake has not been seen.
The few symptoms of the bite include: tightening of the facial muscles in one to two hours of the bite; inability of the bite victim to see or talk, and, if left untreated, the patient may die from respiratory paralysis within four to five hours. A clinical toxicology study gives an untreated mortality rate of 70-80%.
Again, the last paragraph is key. I'm trying to compare spiders, which rarely kill, to a snake which kills when it bites 75% of the time on untreated victims. So, if anything, what people rightly need to fear when going to somewhere in Australia is snakes.
Now, I don't want to scare anyone here, I'm just giving a damn tonne of clarification (which I hope is correct by all means). The reason for all of the deaths in India by snakes is largely due to how the majority of the population have insufficient means to prevent snakes from simply slithering into their house and biting. Simple things like a raised bed and at the very least a door to a house would slice the amount of deaths considerably. And since most of Australia's citizens are much better off than the lower class of citizens in India, it is still a rare thing to be expect.
I'm also not trying to say people's irrational fear is stupid because of the greater dangers in the world, as I completely understand the topic of irrational fear in itself. This wall of text is mainly meant to be informing, not disproving or ridiculing. There is a lot of misleading information in the world that exaggerates the dangers of something and as a result causes some unjustified fears of them which would otherwise not occur if the person fully understood the danger.