A poison is any substance that causes injury, disease, or death through chemical means when ingested, inhaled, or otherwise absorbed into the body. Household cleaners, medicine, pesticides, gasoline, and certain plants and animals can all be poisonous.
Toxins are poisons produced by living organisms (e.g., animals, plants, fungi, and bacteria), and may be used for defense or predation.
Venom is a type of toxin secreted by some animals (such as spiders, wasps, snakes, and fish) that is injected into victims by stinging or biting.
- The term poisonous is applied to organisms that are harmful when touched or eaten, and the term venomous is reserved for animals that deliver their toxins by biting or stinging.
- If an animal is poisonous, its entire body (or large parts of it) will contain poison. Venom is only found in specialized venom glands.
- Poisonous organisms usually use their poison defensively, to avoid being eaten; venomous animals can use their venom to immobilize pray, or as a defense mechanism.
- While poison is harmful if consumed, venom usually isn’t.