Okay, so my local feed store is having a great chick supply sale and I bought one of those galvanized 12 gallon feeders for my 4 week olds. They out grew the little mason jar feeder with the holes. Now I am realizing that they will try to sit on the edges of the open top and probably poop in the feed. Any suggestions for a secure lid? I can just put a board on it, but I am affraid they will knock it off when jumping up there.