While the blue-ringed octopus is only about the size of a golf ball and its glowing rings are pretty, it's also one of the deadliest animals on the planet. Blue-ringed octopuses flash their blue rings when danger occurs, and they're armed with a powerful toxin--tetrodotoxin. These critters are unique in that they are both venomous and poisonous! Readers get the chance to see these amazing animals up close without worrying about being bitten. The text...