A pet peeve of mine is the use of the term "poisonous" when the word "venomous" is intended.
Venom is an offensive weapon that is actively injected directly into the body, and attacks either the nerves or the blood (or both). The term "venomous" implies that it will attack it you and cause major pain and/or paralysis.
Poison is a substance that is taken up by the victim, e.g., through the digestive or respiratory system. In the context of ecology, it is a defensive weapon. The term "poisonous" implies that it will make you sick or kill you if you eat it or inhale it.
So, snakes, spiders, wasps and sea anemones are
venomous.
And, poison-dart frogs, millipedes and poison ivy are
poisonous.
-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.