If you're hiking and hear something rattling, chances are it's a rattlesnake. They slither onto trails this time of year when the weather gets warmer.
"I think the busy trails..I think they're scared, right? I think it's more when you're by yourself I've heard," said Tina Nowling.
"I've seen a few rattlesnakes over the course of three or four in 15 years," said John. "Yes, I've seen them here, they're up the side of the trail, about half way up a rock wall..they're tucked in the rocks."
"Usually, if you're gonna find snakes, they're on the other side in the evening," added Tres MacCollum.
Valley hiking trails are very busy this time of year and if you venture out, chances are you may hear, see or possibly even feel something pretty startling.
"So when the weather is nice, there's the most pedestrians on the trail, but there's also the greatest incidence of creepy crawlies coming out on the trail because they're cold blooded, trying to warm themselves up," said Chris Ketterer of the Phoenix Fire Department.
Even fire fighter Michael DuBois has nearly been bit on his leg while fighting a summer brush fire.
"Pulled my pants up and had not gone through these bunker pants, but a day later, it left a bruise as big as an orange," he said.
Ketterer adds, "Half of all fatalities in the U.S. occur from rattlers, so they're very very dangerous and neurotoxins when they envenomate."
A sobering reminder as beautiful as it is. When you're out, you must embrace all mother nature has to offer.
You should always keep a cell phone with you just in case you need to call for help.