Pigeons/animals lead simple life’s, well that is until you study them ;D. We the fancier control when they eat, drink, rest and procreate, the four main things they live for, withhold any of these and they let you know about it. Get them into a routine, when you exercise when you feed etc they start to tell you when the time for these things are. To me 'what makes them tick' is tapping into these things (eat, drink, rest and procreate) and trying to understand what they're trying to tell you. By studying them individually you can evaluate a pigeon better than any eye sign or by handling the pigeon or by the conformity of its body. I look for their character, I've found the more the character the better the pigeon. The characteristic I like best in a pigeon is the one where they're studying me, look for them they're there.