The Brazilian wandering spider is the most venomous spider in the world. This aggressive spider’s venom is so toxic that only 0.006 mg (0.00000021 oz) of the substance is all that’s needed to kill a mouse. A deadly bite from this spider causes intense pain and inflammation as well as loss of muscle control and difficulty breathing. This can lead to paralysis and asphyxiation if not treated. Fortunately, there is a very effective antivenom available.
photo: João P. Burini /wikicommos