Occasionally I call them something based on some trait that really stands out. A very friendly Ameraucana with prominent muffs or "mutton chops" we called Mutter or Mutt. She came when you called her name. Friendly chick that was a single hatchling was called Little Red, and so on. But the friendly ones get picked off by predators more readily since they are less flighty. I really don't name them or think of them as pets anymore. I refer to them by a trait if I'm telling my husband about one, such as "the jabbery red".