I had black widows all over the place when I lived in the San Fernando Valley. Even saw a little rattlesnake under a big pile of wood. I also used to do pest control bleah..
Black Widows won't generally hurt you unless you sit on them or something. It's best to kill them since the bite is so fucking nasty but they're nothing to get too worried about if they're around. Just look into any dark corners before you stick your hand in there and watch what you're sitting on
