With the advent of spring, it is now fly season, whence the birds like to eat.
So plenty of birds light on the porch railing to spy the flies,
whence, leaving plenty of unsanitary droppings on said railing.
I tie empty clear plastic water bottles to the railing and let them fly in the breeze,
of which there is here, 90% of the time,
Making a nice, soft bobbing sound against the vinyl rails.