You see the green and red color combination of BirdFaucet? This red tip at the end of the green stem intrigues your birds to peck at it thinking it is some kind of fruit. Also, if your water pressure is 5 PSI, then, over a few hours, it will have a drop of water forming at the tip of the water nipple. When birds peck at it, they will get more water and thus the birds learn. Most birds will try it in a matter of days unless your bird pens are thousands of square feet and is filled with hundreds of objects red in color to peck at.