People have evolved to fear snakes out of necessity. One bite from a venomous snake can be fatal! So it is ironic that a number of remarkable drugs come from poisonous snakes and other deadly creatures. Researchers increasingly prize this group of animals, believing their venom can treat major disorders ranging from high blood pressure, to heart disease, and cancer.

So, why is venom made into lifesaving drugs? Take the Brazilian pit viper - it incapacitates its victims by causing their blood pressure to plummet. But when molecules in the venom are developed into therapeutic drugs such as ACE inhibitors, they lower high blood pressure by decreasing chemicals that tighten blood vessels so that blood flows more smoothly.

Another drug called tirofiban comes from the saw-scaled viper, whose venom thins the blood and causes victims to bleed out. As a drug, it's an anticoagulant that clears blood clots in people with a minor or impending heart attack.

Another snake venom, from the Malayan pit viper, also thins blood. However, its venom possesses a protein that may dissolve blood clots in stroke victims up to six hours after the first symptoms appear. That would improve on the three hour window of existing drugs, and save a lot more lives.

Scientists are venturing beyond snake venom. The deathstalker scorpion is a bright yellow spider whose bites can be fatal. Yet, its venom contains chlorotoxin which just happens to attach to cancer cells by binding strongly to a cancer specific protein. By fluorescently labeling chlorotoxin, surgeons can identify and remove cancer tissue. Chlorotoxin can also be used to kill cancer cells by delivering radioactivity directly to tumors.

While this is all great news, scientists are concerned negative environmental impacts on the habitat of exotic species will limit their work. Ultimately, that's fewer life saving drugs available to all of us.