We copied your version of the feeder, via looking at your picture, but it doesn't seem to replinish itself when they have eaten all the food in the bottom part of it. How does the food just move on down? I put a cap on the top so that rain wouldn't get in, then we cut slits in it for air flo but it still doesn't seem to go on out, is your slanted and I can't tell from picture? Please advise. Thank you!