I spent a whole day putting coils of wire on their perches. It was hard work, balancing atop a ladder, holding a wooden pole with a notch cut at the end, loosely holding the wire coil. Nevertheless, the birds kept trying to land where they couldn't - until nightfall, when they simply had to. Plastic snakes laid along the rafters. 24 hours later, one pigeon is blithely roosting on top of a plastic snake realistic enough to scare a baby.
Pigeons are certainly damnfool persistent creatures.
I remember reading some interesting stuff about pigeons when I was a student. Every pigeon has his own 'explanation', his own personal philosophy of how the world works, for him. Whatever the last thing was that the pigeon was doing just before the food came down the chute, gets to be repeated more often, so a correlation develops between that behaviour and the next dose of food. For a cognitive psychologist, the explanation is that the pigeon has formed a hypothesis, a belief that he has hit upon the cause of what makes the food come along. He then tests the hypothesis, and makes a statistical judgement.