However even 18 hours is not considered abnormal for a Chihuahua. This includes naps.There are 2 types of sleeping. One is a lighter sleep (called slow wave) and the other is the deeper sleep (known as REM-Rapid Eye Movement). Dogs, just like humans do have these 2 different types of sleep.
Probably the best known snake in the world, the Rattlesnake is a pit viper found almost everywhere in the United States, and is capable of a deadly bite. Its trademark rattle strikes fear into anyone who hears it.
The Crotalinae, commonly known as pit vipers, crotaline snakes, or pit adders, are a subfamily of venomous vipers found in Eurasia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head. Currently, 18 genera and 151 species are recognized: seven genera and 54 species in the Old World, against a greater diversity of 11 genera and 97 species in the New World. These are also the only viperids found in t