The National Wildlife Federation, rattlesnakes "are highly specialized, venomous reptiles with large bodies and triangle-shaped heads." The federation said it’s one of the most iconic groups on North American snakes due to the "rattle" at the tip of the trail. RELATED: Puppy trapped beneath family's deck rescued by firefighters in IowaThe federation said rattlesnakes are found in almost every part of the continental United States but are common in the southwest.According to the Natural History Museum, Los Angeles County, each year, around 7,000–8,000 people are bitten by venomous snakes in the U.S.— a fraction of the country’s total population.