Which do you prefer- cups or nipples? I don't even have chickens but I'm planning on getting some in the spring. I've been researching feed and watering systems. Cups seem okay, but it seems like dirt still gathers in the cup and you have to rinse them out... also, people have trouble teaching chickens to use them? Nipples seem better to me... people seem to say they are preferable to chickens and that chickens take to them pretty quickly. I guess they prefer stretching their necks to drink? Some people say they leak. What brands have you tried that don't leak? Also, how to you heat your cup/nipple watering system? I was thinking of rain gutter cable- or a submersible aquarium heater- Thanks!