What is the difference between venomous and poisonous animals?

The answer

The distinction lies in the delivery mechanism. Venomous animals actively inject toxins into another organism through specialized structures like fangs, stingers, spines, or nematocysts, as seen in snakes, scorpions, and jellyfish. Poisonous animals carry toxins that are harmful when ingested, inhaled, or touched, such as poison dart frogs whose skin secretions contain batrachotoxin, or the pufferfish that accumulates tetrodotoxin in its organs. Some rare animals are both: the blue-ringed octopus is venomous (it bites) while also being poisonous (its flesh is toxic if eaten). The Asian tiger keelback snake is another dual-threat species, producing venom in its fangs while also sequestering toxins from the toads it eats in specialized neck glands.