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 Viperidae (vipers) is a family of venomous snakes found in most parts of the world, excluding Antarctica, Australia, New Zealand, Madagascar, Hawaii, various other isolated islands, and north of the Arctic Circle. All have relatively long, hinged fangs that permit deep penetration and injection of venom. Four subfamilies are currently recognised. They are also known as viperids. The name viper is derived from the Latin word, vipera, -ae, which means viper.