Coyotes
Coyotes are seen in the wild as well as in more urban areas around the city. There have been several reported incidents of coyotes attacking and killing pets in some of the Las Vegas neighborhoods. However, they will almost always avoid contact with people.
Mountain Lions (Cougars)
The Red Rock Canyon National Conservation Area as well as the Valley of Fire have had frequent mountain lion and bobcat sightings. The animals tend to stay away from populated areas. At dusk, in more remote areas, it is possible to hear the mountain lion cry, a loud high pitched noise.
Rattle Snakes
Beware of poisonous animals like rattlesnakes and scorpions. They are commonly found across the Mojave and the Great Basin, and tend to be more active in the summer. There exist several species of rattlesnake and some can be more aggressive than others. During the winter the snakes might seek warmer areas closer to human settlements. An interesting fact is that not all species of rattlesnake rattle, and some might stop rattling when exposed to lower temperatures.
Spiders
Black Widow spiders and Desert Tarantulas are common in the desert surrounding Las Vegas. Though neither are actively aggressive towards humans. The Black Widow is one of the most common spider species in Nevada, and is extremely dangerous because of its strong defensive behaviors. It will immediately attack and bite when threatened or disturbed. The venom of the Black Widow is considered to be 15 times stronger than that of a rattlesnake.
Wild Horses
Las Vegas has a relatively large population of feral Horses and Burros, especially in the Red Rock Canyon National Conservation Area. These animals are not that afraid of people and are used to getting food from tourists and hikers even though this is forbidden by the city. Several incidents of feral Burros biting and kicking hikers have been reported.
Desert Bighorn sheep
Bighorns are beautiful and fairly common in the surrounding mountains. They can often be sighted around the Red Rock Canyon National Conservation Area, the Willow Springs Picnic Area and along Highway 93 near the Hoover Dam. Caution should be taken when picnicking with a Bighorn in sight, they have been known to try to steal food.
