Did you know that most so-called poisonous snakes aren't poisonous at all, but actually venomous?
"Poisonous" describes a plant, animal, or anything else that is toxic or harmful if you eat it or touch it. "Venomous," on the other hand, refers to animals that inject a toxin directly into their prey to subdue them, or in self-defense against a predator.
Venoms, produced by some animals in specialized glands, are injected into prey by biting, stabbing, or stinging. For example, a rattlesnake bite is venomous and sometimes lethal, but you can touch, and even eat rattlesnakes without ill-effects because they are not poisonous.
The Dart Poison Frogs in Central and South America are a good example of a poisonous animal. They are toxic if you ingest even a tiny bit of the secretions from their skin. In fact most amphibians have poison-secreting glands in their skin that make them unpalatable or even deadly to predators.
The Dart Poison Frogs and some salamanders are among the most poisonous animals in the world. Many animals don't produce their own poisons, but have evolved the capacity to ingest toxic plants or animals and store those toxins in their own bodies, which makes them poisonous to other predators.