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.
Vipers (Viperidae) are a group of snakes known for their long fangs and venomous bite. Vipers include true vipers, bush vipers, rattlesnakes, pit vipers, adders and night adders. The fangs of vipers are long and hollow and enable the snake to inject venom into animals that it bites. Venom is produced by and stored in glands located at the back of the snake's upper jaw. When the snake's mouth is closed, the fangs recede into a thin membrane and fold against the roof of the snake's mouth.