Getting ready to order some water nipples for my chickens. While I'm at it, would also like to get some for rabbits. In researching, it appears there is a difference between the ones for rabbits and chickens. What is the difference, and is it important, if so in what ways? Are some acceptable for both? There are big price differences between them, and also between the ones for the same animal. Will rabbits chew on the ones made with plastic, or should I use brass ones? What good and bad experiences have you had? TNX.