Hi Jerry. Eight years - wow. I'm still raising mine and things are going well. I hadn't thought about the flushing idea - I'm sure you have mentioned it, but I just missed it. I'll do that.
Yesterday I took some old bread, put a glob of peanut butter in the middle, balled it up soaked it in water squeezed out the excess, and put in the freezer. I think our little friends will enjoy that snack today.