The birds sit at the feeder and toss aside about half of the seed in the feeder. That ends up on the ground and over the past four years, it’s turned into quite a pile of birdseed. Enough so that all the mice in the neighborhood have moved into our yard to enjoy the feast. To mitigate that, today I built a screen tray to hang below the feeders. What the birds toss aside ends up on the tray. Other birds like feeding from the tray rather than from the bird feeders, anyway, so we get a double payoff.