Arizona Bark Scorpions (Centruroides sculpturatus, Ewing 1928; also known as Centruroides exilicauda, Wood, 1863) are small bodied scorpions that inhabit the Mojave and Sonoran Desert regions of the American southwest and also extend to parts of northern Mexico. In this species, females are significantly larger than males. In nature, Bark scorpions are often found on rocky hillsides, outcrops, and riparian habitats. However, this species has been extremely successful at invading urban areas, and within neighborhoods, can be found along cinderblock walls, under piled debris, and even among landscape vegetation. Bark scorpions are the most venomous scorpion species in North America, and use their venom to subdue invertebrate prey (e.g. crickets, moths, cockroaches, spiders and centipedes). Female Bark Scorpions are viviparous (which means that they give live birth). A female Bark Scorpion can produce as many as 30 offspring at a time! After the offspring are born, the female will care for her offspring by carrying them on her back for a period of a few days to a couple weeks. Following the maternal care period, the offspring will disperse and are capable of surviving on their own.
Sidewinder Rattlesnakes (Crotalus cerastes) are small-bodied snakes that inhabit sandy washes, dunes, and desert flats in the deserts of southwestern North America. Female Sidewinders are significantly larger than males. Sidewinders get their name from their unique mode of locomotion called “sidewinding”. Sidewinding allows these snakes to move efficiently over loose or sandy soil. These snakes can also be identified by enlarged supraocular scales (above their eyes). Sidewinders spend most of their time in rodent burrows, coiled underneath vegetation, or cratering within sand. Sidewinders are venomous ambush predators, and will sit and wait for their prey to come within striking distance. Sidewinders are known to feed on lizards, mammals and birds. Female Sidewinders are viviparous, and can give live birth to 1–20 young during late summer to early fall (Ernst and Ernst, 2003). Young Sidewinder rattlesnakes are known to use their tails as lures to attract small lizard prey (Reiserer and Schuett, 2008). This behavior is referred to as “caudal luring”.