The Rock Rattlesnake, or the Banded Rock Rattlesnake, is a small pit viper in the southwestern United States and northern Mexico. Its body has a pinkish-brown to dark-gray color that allows it to blend in with the surroundings.

It preys on small mammals, lizards, birds, and amphibians at night. This ovoviviparous species gives birth to 2 to 8 offspring at a time, usually in late summer or early fall. 

Despite its venom, it usually does not pose a threat to humans unless it feels threatened.

The Speckled Rattlesnake, or Mitchell’s Rattlesnake, is a venomous pit viper in the western US and Mexico. It blends in with the rocky terrain thanks to its speckled skin. 

It is active at night, feeds on small mammals, birds, and lizards, and gives birth to live young. 

When threatened, this type of rattlesnake rattles its tail and strikes with potent venom. A recent study reports its venom constitutes crotoxin and serine proteases2, which can lead to muscle weakness, vision problems, and uncontrolled bleeding.

Grand Canyon Rattlesnake, also called the Pink Rattlesnake, inhabits the Arizona and Utah states of the USA. Its colors, ranging from pink to grey, resemble the surrounding rocks, allowing it to blend into the Grand Canyon's stunning landscape. 

Unlike most nocturnal rattlesnakes, the Grand Canyon Rattlesnake prefers the cooler daylight hours to hunt for small mammals such as mice and rats. However, it may occasionally prey on birds.

This rattlesnake is a small, primarily nocturnal creature found in the southwestern United States and northern Mexico. It can only grow up to 32 inches. Depending on their rocky environment, their color can range from light grey to pink, with mottled patterns of different hues.

It uses the ambush technique to hunt small mammals, lizards, and birds. Unlike other types of rattlesnakes, they are active in colder temperatures.

Banded Rock Rattlesnake (Crotalus lepidus klauberi) found in the Sierra Madre Occidental of eastern Sonora, Mexico.

The Northwestern Neotropical Rattlesnake lives in Southwestern Mexico, with some staying at  Sierra de Coalcomán, reaching elevations up to 6,500 feet. It has a unique skin coloration and can grow around 3.2 feet in length. 

This type of rattlesnake is terrestrial and diurnal, feeding on rodents, birds, and lizards.

Crotalus culminatus syn. Crotalus durissus culminatus at the San Diego Zoo, California, USA

The Baja California Rattlesnake, also called Lower California rattlesnake, is a snake living in Mexico's Baja California Peninsula and the southern tip of California. 

It is relatively small, reaching up to 35 inches, and has a distinctive skin coloration that blends with its desert environments. 

Moreover, it preys mainly on rodents and lizards. Unlike most rattlesnakes, they also eat centipedes of the genus3 Scolopendra.

A curious axolotl fact is that they do not have eyelids, so they sleep with their eyes open, making it difficult to tell when your pet axolotl is awake or asleep. Knowing if axolotl is awake or asleep at night is more difficult.

However, as a nocturnal creature, it is active at night and sleeps during the day. Some signs that show when an axolotl is asleep include stillness of gills and other body activities. It will also most likely retreat to its hiding space when it wants to sleep.

The Eastern Gray Squirrels live in woodlands and urban areas throughout the eastern and midwestern US and eastern provinces of Canada2. 

These agile creatures are most active during sunrise and sunset. Eastern Gray Squirrels also store food in secret stashes, which benefits them and the environment by spreading seeds far and wide.

One of their most impressive tricks is their unique agility. For instance, their ankles can rotate 180 degrees, allowing them to make a death-defying head-first descent down trees.

The Southern Flying Squirrel is a small squirrel species with unique nocturnal adaptations. 

They possess large eyes perfectly adapted for nocturnal adventures and a flap of skin3, called 'patagium,' that stretches from wrist to ankle, allowing them to glide from tree to tree. 

These squirrels live in deciduous and mixed forests and prefer to build their nests in tree cavities. Additionally, the Southern Flying Squirrels huddle together for warmth during the winter season. 

Their diet comprises nuts, seeds, fruits, insects, bird eggs, and small birds. 

Moreover, they play a significant role in their ecosystems by planting the seeds of new forests and being a food source for larger predators.

Northern Flying Squirrels are expert gliders that use a skin-like membrane called the patagium to navigate their treetop homes. 

They typically live in mature, dense forests where they have access to a variety of food, including fungi, which they help to disperse by scattering spores. 

These squirrels also huddle in their nests to keep warm during cold temperatures.