After manufacturing buckets with the vertical nipples I've transitioned to the horizontal nipples. I use them for my own backyard flock and will never go back to the old buckets and bowls. I'm wondering, however, why there seems to be concern about the horizontal nipples. Bird breeders in my area use them in their chick brooders as well as their adult bird enclosures and are very happy. However, I've read some posts here on BYC voicing concern that their birds might not be using them. ??? Thoughts? Have you tried horizontal nipples with your birds?