Africanized bees, Western diamondbacks, a cougar or two on rare occasions, javelinas, gila monsters... The only thing I worry about are the bees 'coz I hike a lot by myself. Cougars only come down from the mountains during extreme droughts, the rest are really part of the landscape and they're easy to deal with if you use common sense.
All that plus Bark Scorpions, Wasps and Black Widows.
Maybe I should put them in risk order.
Africanized bees
Rattle snakes
Mountain Lions
Bark Scorpions
The rest really don't matter to me because the risk is so low. Bees are the worst because they're fast and if you injure yourself while fleeing you're screwed. These can be a threat whether you're in a mall parking lot or in the boonies. The threat is higher in the boonies because you don't have a vehicle or indoor place to flee to. Your only chance is to put enough distance between you and the hive. Africanized bees pursuit longer than honeybee's and often give chase for several hundred meters once the first sting has occured. They're a big threat to the elderly and pets.
Rattlesnakes are second on my list because although my exposure is limited, the result of being invenomated is very bad. They are hard to see and don't always rattle first. They're also fairly common and I see them while hiking, biking, working, hunting and they've even come up onto the back patio at night. Stepping directly on one would be the worst case scenaro.
Mountain Lions although not existing in large numbers and rarely seen are out there. They typically avoid humans and usually flee but sometimes, for whatever reason, they loose their fear and decide to stalk human prey. I think about them the most when hunting in the high country while walking in the dark and while mountain biking in the foothills. I carry pepper spray and a large folding knife as a last ditch defence. Most people who are killed are unarmed or have no one else around to help them. I can't imagine spending time as an outdoorsman in west without at least carrying a small knife. One 61 year old man in Port Alice actually saved life using an old school, Buck style folder, by stabing back over his shoulder as the cat bit at his neck from behind. He slit the cougar's throat and it died on the gravel road that the man had been walking on. Without that knife he would have been eaten.
Bark Scorpions because they do make it into the house sometimes. They're a light transluscent tan and difficult to see. If you're walking barefoot in the house and step on one there is a good chance of getting tagged. Most folks out here no better than to reach down and pick up something from the floor without knowing exactly what it is first. It's not uncommon for someone new to the state to reach down to pick up a piece of "lint" only to find out the hard way that it wasn't just lint. I've been stung in the toe once and it felt like a match burning between my toes. I had numbness to all my extremities including my lips, ears, oposite foot and all my finger tips. I don't consider them life threatening but they'll sure ruin your next 24 hours. Although the numbness everywhere else went away fairly quick, my toe took 6 weeks for all the feeling to return.
and they make a ratchet at night)
