When a city puts up a sign like "Use Caution, Active Bees in Area," the bee-sensitive among us (as in most people) tend to go on yellow alert. These signs, which you can find at at Camelback Mountain, shouldn't be taken lightly. Killer bees live up to their name in metro Phoenix, where they've nailed several young hikers in local mountain parks. As recently as 2016, a 23-year-old man hiking Maricopa County's Usery Park was stung to death. But as usual, Camelback Mountain, the popular and over-used landmark in east Phoenix, wins out for the craziest tragedies. In 2004, and again in 2012, young men climbing the cliffs in Echo Canyon slipped and fell in the panicky minutes after a swarming attack began. Another climber in 2009 received 120 stings. Hikers on the main trails aren't usually the victims. But they could be. We've got bees on the brain because this year we heard bees while hiking Echo Canyon. No bees were in sight, but their frightful sound came suddenly, airplane-loud. A swarm was on the move. Hike or climb to Camelback's less-visited spots, and you just might find it.