precarious situations

people use the term "bird on a wire" to denote a precarious situation. but when you think about it, a bird on a wire isn't that shaky. i mean, look at their little feets. those little claw thingies wrap around a wire just perfectly. and they have a great sense of balance. i mean, they're used to standing on two feet cause well, thats all they have. now....a hyena on a wire is a whole different story. That critter could fall at any minute. so from now on, i'm going to say "hyena on a wire" and you'll know exactly what i'm talking about. ok?