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.
Snake species. The United States has about 20 species of venomous snakes, which include 16 species of rattlesnakes, two species of coral snakes, one species of cottonmouth (or water moccasin), and one species of copperhead. At least one type of venomous snake is found in every state except Alaska and Hawaii.