Scorpions are 8-legged arachnids (distantly related to spiders) recognized by the two crab-like pincers at the front end, a flattened body, and a long tail with stinger on the back end. Like other arachnids, scorpions have a head, thorax, and abdomen. However, in scorpions, the head and thorax are combined to form a cephalothorax, and the abdomen is elongate and forms the tail. Because the "tail" is the abdomen, the intestines are in the tail, and the anus is at the end of the tail, just ahead of the telson (bulbous poison gland with stinger).

Around Las Vegas, most scorpions are small, but the largest species grown to about 5-1/2 inches long. Colors of the different species range from blackish to yellowish (straw).

Scorpions are most active at night, and most species live on the ground. Some species make burrows, while others just hide under logs, rocks, boards, and trash. Bark scorpions live on vertical surfaces such as trees, bushes, and walls.

Scorpions feed on anything they can catch, but mostly soft-bodied insects, crickets, roaches, and spiders. They also eat other scorpions, even their own kind and their own young. The larger species can catch and eat small vertebrates such as lizards, mice, and hatchling desert tortoises.

In the fall or early spring, male and a female scorpions pair off and engage in an elaborate courtship dance that may last several hours. After mating, in which the male entices the female to pick up a packet of sperm, the female will eat the male if he can't get away. Females give birth to a litter of up to about 100 live young about a year later. The young climb on their mother's back and remain there until after the first molt, when they leave the mother to fend for themselves. Immature scorpions molt several times before reaching maturity about one year later.

Scorpions are extremely common in some parts of the desert, especially in sandy places with lots of shrubs and in places with fallen logs (such as Cottonwood groves), but they are also very skittish and hard to find. Scorpions glow under black lights, making black lights useful for finding them at night.

The scorpions of Nevada are a numerous and diverse group, including some 15 species representing eight genera and four families:

• Bark Scorpion (Centruroides sculpturatus)

• Anuroctonus phaiodactylus
• Giant Desert Hairy Scorpion (Hadrurus arizonensis)
• Northern Desert (Black) Hairy Scorpion (Hadrurus spadix)

• Superstitionia donensis

• Paruroctonus arenicola
• Paruroctonus becki
• Paruroctonus boreus
• Paruroctonus luteolus
• Paruroctonus shulovi
• Paruroctonus simulatus
• Serradigitus wupatkiensis
• Smeringurus vachoni
• Vaejovis confusus
• Vaejovis hirsuticauda.

Scorpion Stings

Scorpions sting; they do not bite, although they can pinch. All scorpions are venomous, but most are harmless to humans. In general, the smaller the species, the more dangerous it is for humans (of course, it is hard to tell juveniles of a large species from adults of a small species). Bark scorpions are the main problem around Las Vegas because their stings can be deadly. However, the stings of other species are not serious and usually result in localized pain with some swelling and tenderness. Some people are allergic to scorpion venom, and if a sting seems serious, call the National Poison Control Center toll-free at (800) 222-1222.

Most scorpion venom destroys red blood cells, producing localized discoloration at the sting site and painful swelling. However, bark scorpion venom is neurotoxic and causes little swelling and discoloration. Reactions to bark scorpion venom include restlessness, convulsions, staggering gait, thick tongue sensation, slurred speech, drooling, excessive sensitivity of skin, muscle twitches, abdominal pain and cramps, and respiratory depression. These symptoms usually subside within 48 hours, but should be treated by a doctor.

If you get stung, consider calling the National Poison Control Center toll-free at (800) 222-1222. This number is good for emergency information as well as general information and questions.