Tarantulas inject a paralyzing venom into prey with their large fangs. However, tarantulas rarely bite humans, and although the bite may be painful, the venom is generally no more serious that a bee sting.
Tarantulas move their jaws vertically, or up and down.
The majority of spiders belong to the suborder Labidognatha, or araneomorph spiders, which includes both the hunting spiders and the web spinners. These spiders are easily distinguished from tarantulas because they move their jaws sideways, like a pair of pliers. However, it is necessary for the tarantula to be in a fairly moist environment where the temperature ranges from 75 degrees to 82 degrees Fahrenheit, for there to be successful molting. As a spider nears molting, it becomes more sluggish and stops feeding. Some spiders flip on their backs to molt, while others lay on their sides.