They're big, they're scary as hell and they seemingly show no fear of human beings. So what if palo verde beetles are basically harmless? Many a Tucson newcomer has nearly soiled his or her britches the first time one of these gargantuan insects came straight toward them. It's the weird noise they make and the fact that they're horror-movie-sized (3-inch-long bugs, eek!) that makes them so scary. If one somehow manages to get inside your home, then you may be forced to move.