TWO-DRAWER / TWO-DOOR STACK: This device is made up of four 2-inch square cubes that are stacked on top of each other. Two of these cubes have slide-out doors, and two have pull-out drawers, and each cube opens from a different side. You can easily reposition the cubes and/or the openings to continue stimulating your pet bird’s interest.     The parrot must stand on one foot, hold the device steady with the other foot and open the door or drawer with its beak to collect the food items. The Two-Drawer/Two-Door Stack device requires good balance and coordination. The bird must have enough experience and self confidence to know that determination and hard work will result in a reward.     Fill the compartments with a combination of favorite familiar food items mixed with something new. Due to the effort required, the bird should be rewarded with something it enjoys, and, because of that effort, it will be more receptive to something new.