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10 creatures that deliver the most painful stings and bites

By: Bryan Nelson on July 25, 2011, 10:40 a.m.
A bark scorpion crawls along a rock

Photo: IrinaK/Shutterstock

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Arizona bark scorpion

These are the most venomous scorpions in North America — a frightening fact considering that this is the most commonly encountered house scorpion in Arizona. The venom causes acute pain and can lead to frothing at the mouth, breathing difficulties and muscle convulsions. Limbs may become immobilized. Though the venom is rarely fatal, its effects can last for as long as 72 excruciating hours.