The terms poisonous and venomous are often used interchangeably to mean the same thing: an animal possessing toxins that could harm or kill you. This is somewhat true but does not paint a complete picture - poisonous and venomous actually describe the animal's method of injecting these toxins.
Discover what poisonous, venomous, and toxic really mean and how we can apply these terms to the animal kingdom.
What Is a Poisonous Animal?
Poisonous is a term used to describe something that can be harmful or deadly if ingested, inhaled, or absorbed through the skin. It can refer to plants and animals capable of producing toxins that can cause harm to humans and other living organisms.
Poisonous animals possess venom or toxins in their bodies, which can be used to harm or even kill other animals. These animals have evolved to protect themselves from predators, and many of them have developed sophisticated defense mechanisms. They may be deadly, but poisonous animals have grown to be more passive than venomous creatures, relying on defensive rather than offensive strategies for survival.
Hawksbill sea turtles are an endangered species of marine turtle found in tropical and subtropical oceans worldwide. They are primarily non-aggressive and will only bite if provoked or threatened. However, with a diet that includes toxic sponges and algae, this sea creature can be extremely dangerous if it is consumed. For humans, consuming this turtle's flesh can lead to chelonitoxism (or marine turtle poisoning), which causes an array of stomach issues such as nausea and vomiting.
Cane toads release bufotoxin (one of the world's most poisonous toxins) from their shoulder glands whenever they feel threatened. This toxin can kill an average-sized dog in just 15 minutes and causes significant harm to humans, with symptoms ranging from gastrointestinal issues to sudden death.
What Is a Venomous Animal?
Venomous is a term used to describe an animal or plant that produces venom - a type of poison injected into another organism's body, typically through a bite or sting. These toxins must be injected because they are a combination of large and small molecules, so they require a wound to enter the body and find their way into the bloodstream. Only here can they cause optimum damage.
These animals are far more vicious than their poisonous counterparts, as they have to actively deliver their toxic attack via a bite or sting.
The box jellyfish is generally considered the most venomous animal in the world. It has tentacles lined with thousands of tiny stingers, each capable of injecting venom into its prey; this venom can cause extreme pain and even death in humans.
Snakes are famously venomous creatures and account for some 200,000 human deaths every year. The elusive Inland Taipan is considered the most venomous snake in the world, with the highest median lethal dose of venom. However, this shy reptile rarely attacks humans, so it is generally considered less dangerous than more aggressive species such as the saw-scaled viper.
Venomous mammals are less common but do exist in the animal kingdom. Among the most prominent is the duck-billed platypus, which has venom-delivering spurs on its hind legs. One kick from this unique creature is enough to kill small mammals, such as dogs, and can cause excruciating pain for larger animals, such as humans.
Meanwhile, the innocent-looking slow loris has its own deadly form of defense. When threatened, these mammals raise their arms to access venom-producing glands; as they lick the venom from their armpits, it settles into the grooves of their canines - teeth that are strong enough to pierce bone. This bite is excruciating and can be lethal in certain circumstances.
What Is a Toxic Animal?
The word "toxic" is often used to describe a substance or situation hazardous to one's health. Toxic animals can cause harm or even death to humans and other animals by producing toxins. These toxins can be transferred to other animals via injection, inhalation, absorption, or any other transfer method. Therefore, poisonous, and venomous animals can be described as "toxic."
Most animals are either poisonous or venomous, but there are a few which are both. The Blue Ringed octopus, for example, is a venomous sea creature that injects its toxin through a bite. But, this animal is also poisonous due to the myriad of toxins in its body; the most potent is tetrodotoxin which causes a slow paralysis of the muscles.
Asian Tiger snakes are another example of creatures that are both venomous and poisonous. They produce a deadly cocktail of toxins to deliver to victims through a powerful bite, but they also store toxins in their skin, making them poisonous if eaten.
Then there are the poisonous creatures who have found a way to weaponize their toxins. Enter the Greening's frog and Bruno's casque-headed frog, the only two frogs currently classified as venomous. The poisonous nature of these frogs has long been understood, but recent research shows impressive defense capabilities. When backed into a corner, these hardy frogs use spines on their heads and lips to inject these toxins into their victims, thus making them venomous as well as poisonous.