1. Box jellyfish The venom's toxins can cause extreme pain, paralysis, delirium, shock, cardiac arrest and even death within minutes. The jellyfish has enough venom to kill 60 adults.
1. Botulinum toxin. Scientists differ about the relative toxicities of substances, but they seem to agree that botulinum toxin, produced by anaerobic bacteria, is the most toxic substance known. Its LD50 is tiny – at most 1 nanogram per kilogram can kill a human.
With adult males averaging 2.59 m (8 ft 6 in) long and weighing 79–91 kg (175–200 lb), the largest species of venomous land animal is the Komodo dragon (Varanus komodoensis), which is also the world's largest lizard.
It's not likely, but humans have the tool kit to evolve venom. Could humans ever evolve venom? It's highly unlikely that people will join rattlesnakes and platypuses among the ranks of venomous animals, but new research reveals that humans do have the tool kit to produce venom — in fact, all reptiles and mammals do.
Human saliva contains a wide variety of bacteria that are usually harmless in the mouth but can cause significant infection if introduced deep within an open wound. It is well known that the bite of a human can often be more serious than the bite of an animal (assuming the animal is free of rabies).
The blue-ringed octopodes (Hapalochlaena spp.) produce tetrodotoxin, which is extremely toxic to even the healthiest adult humans, though the number of actual fatalities they have caused is far lower than the number caused by spiders and snakes, with which human contact is more common.
Australian Box Jellyfish
The box jellyfish is the world's most venomous animal with four species — Chironex fleckeri, Carukia barnesi, Malo kingi, and Chironex yamaguchii — considered highly venomous. The Chironex fleckeri, also known as the Australian box jellyfish is considered the most venomous animal in the world.
The hedgehog (Erinaceidae), the mongoose (Herpestidae), the honey badger (Mellivora capensis) and the opossum are known to be immune to a dose of snake venom.
Blue-ringed octopus
Although it's relatively small -- only the size of a golf ball -- its venom is debilitating and deadly. It can cause respiratory failure within 10 minutes and death within 30. One bite can kill up to 26 men, and there is no antidote.
2. Mosquito. Clocking in at just three millimeters at their smallest, the common mosquito, even tinier than the tsetse fly, ranks as the second most dangerous animal in the world.
4. Dogs: 25,000 people per year. Man's best friend can also be a nightmare. Maulings and bites from rabid dogs are both to blame for the 25,000 dog-related deaths each year.
Venus is an incredibly toxic planet, with an atmosphere that contains 96.5% carbon dioxide and is over 90 times the pressure of Earth's, while its surface temperatures reach an average of 900 degrees Fahrenheit (roughly 480 degrees Celsius).
In terms of the number of humans killed every year, mosquitos by far hold the record, being responsible for between 725,000 and 1,000,000 deaths annually.
Cats, foxes, raccoons, turkeys, pigs, and guinea hens are natural predators of snakes. Having these animals on or around your property is an effective natural way to keep snakes at bay.
Their resistance is to the a-neurotoxin in snake venom, specifically. Domestic pigs have a genetic mutation in their cell receptors that prevents binding of the a-neurotoxin, rendering the venom useless. The resistance doesn't occur in most pigs until they are adults, so small pigs are still vulnerable.
Twenty minutes after being bitten you may be lose the ability to talk. After one hour you're probably comatose, and by six hours, without an antidote, you are dead. A person will experience "pain, paralysis and then death within six hours," says Damaris Rotich, the curator for the snake park in Nairobi.
Australia and Antarctica finally broke apart around 100 million years ago. Today, venomous snakes are found in all of these places – apart from Antarctica, where it is too cold for them to live. On the original combined land mass, it is thought that there was a population of ancestral snakes that was venomous.
Australia's largest extant predator is the dingo C. lupus dingo. There is observational evidence that where dingoes are locally abundant, foxes and cats are rare (Newsome 2001; Glen & Dickman 2005). Dingoes kill these smaller predators, and foxes evidently fear and avoid dingoes (O'Neill 2002; Mitchell & Banks 2005).
The Dingo is Australia's largest terrestrial carnivore, though it occasionally eats plants and fruits. They're opportunistic hunters, but will also scavenge food. The bulk of their diet is made up of meat: they eat kangaroos, wallabies, feral pigs, wombats, small mammals (rabbits, rodents), birds and lizards.
Cardiovascular diseases are the leading cause of death globally. The second biggest cause are cancers.
There are potential health hazards in wound licking due to infection risk, especially in immunocompromised patients. Human saliva contains a wide variety of bacteria that are harmless in the mouth, but that may cause significant infection if introduced into a wound.