Meet the Gila monster, the largest native lizard in the United States. But watch out for its venomous bites.

MEDICINE
Long before developing the polio vaccine, Salk had wanted to be a lawyer and politician.
So-called "Patient Zero" was not, in fact, the first person in North America to contract the virus.
Your spit can tell you much more about your health than whether you should be flossing.
1. A scratch could become deadly.
The peptide only exists in the umbilical cords and circulatory systems of newborn babies for about two weeks; then it disappears.
Ehlers-Danlos Syndrome, Postural Orthostatic Tachycardia Syndrome, and Mast Cell Activation Syndrome are so obscure that most doctors have never heard of them.
Their condition occurs once in every 2.5 million births.
Proteins called ATIs can trigger symptoms of asthma, multiple sclerosis, chronic pain, and more.
Of the wide variety of abandoned buildings, perhaps none are as eerie as deserted hospitals.
A controversial new study finds that humanity may have already reached the peak of its natural lifespan.
An IED took all four of his limbs. A team of 12 surgeons needed 14 hours to replace two of them.
He was the first to figure out that irritating buzz could be a danger sign.
The “patent” in the name didn’t refer to government approval, but proprietary concoctions marketed with extreme promises and flamboyant showmanship.
And around colleges, they're filled with caffeine and nicotine to boot.
Jennie Bushnell was terrified her six children would be seen as freaks—so she kept their remarkable birth a secret.