Animal venoms & poisons

Public often run into confusion to discern between ‘venom’ and ‘poison’ and use them interchangeably, but both nomenclatures are technically distinct to each other. While they are both potentially lethal and harmful toxic substance, their contrasting method of delivery to the victim set them apart from each other.


As specified by biologist, the term poisonous refers to organisms that have toxin substances in their skin or flesh and mandate ingestion, inhalation or contact for negative poisonous consequences to take effect while venomous applies to organisms that inject toxins via biting or sting. It is theoretically possible to drink venom without manifesting any of the toxicity-induced pathophysiology as the toxins proteins would be disintegrated into fragments by acids in your stomach prior to entering bloodstream.


Poisonous animals are mostly passive-aggressive against their prey. They will not initiate attack but release its stored toxins as an aftermath of being ingested, touched or disturbed and that’s how poison find its way to our body system. Cane toad secretes toxins from glands on each shoulder that can bring about harmful effect upon eaten or licked. Most of the snakes are considered as venomous due to its bite-dependent toxin injection mechanism, with garter snake (Thamnophis) being the sole exception as its bite is innocuous but toxic to eat owing to the fact that its body absorbs and stores the toxins of its prey. Puffer fish with toxin-free bite is poisonous if you eat its liver which contains tetrodotoxin.


Venom constitutes myriad of small and large molecules that require a wound for toxins administration into the bloodstream to be effective. As a result, venomous animals are more aggressive in self-defence. Jellyfish injects venom into skin with harpoon-like structures along their tentacles upon contact. Venomous snakes of elapidae origin, specifically cobra, are capable of injecting large amount of venom upon biting during predation or defence against threat.

There are few animals featuring both poisonous and venomous traits. For instance, Asian tiger snake possesses venomous bite while also stores the toxin it acquired from swollen toads in its skin. Blue-ringed octopus upon biting with its beak is venomous but poisonous if it is swallowed as one of the constituents of its venom, tetrodotoxin, can be readily absorbed for its small size.



  1. Australian Academy of Science. (2019). Retrieved from
  2. Rafferty JP. (2019). Retrieved from
  3. Venzel S. (2019). Retrieved from


Prepared by: Chan Yi Wei and Ong Hui Ling

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