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.
Rating Newest Oldest. Best Answer: There are numerous North American snakes which shake their tail if they feel threatened, most of which are harmless. Copperheads and cottonmouths are two venomous snakes which shake their tails like a rattlesnake. Some of the harmless snakes which do this are rat snakes and corn snakes, king snakes, gopher snakes and bull snakes, to name a few. Source(s): madsnakeman Â· 5 years ago.