My feeders are a different make from Stand and Fill, but they are similar. The feeder throw mechanism is supposed to be critter proof and seal off after the spinner does itís job. Well, one seals off if I keep it lubed, but the other one wonít. Dang squirrels can spin me into the poor house on the non-sealing feeder. I wrapped them both in chicken wire today, and itíll take about the strongest squirrel that ever lived to get in there now. I think I Ďwoní, but iím bleeding from a thousand small cuts.