Birds make excellent pets, and their cages are often kept in areas that are heavily trafficked such as living rooms and hallways so they have plenty of the human interaction they crave. However, these area can quickly become littered with sunflower seed hulls and grass seed husks when the birds invariably fling the remnants of their meals everywhere. A good solution for this problem is to fashion a simple homemade seed catcher for the cage.
Hula Hoop Table Cloth Rig
A simple seed catcher solution for a bird cage of small to medium size can be constructed using a hula hoop and an old tablecloth. Stitch two seams of the tablecloth together to form a giant triangular pouch. Stitch the top of the pouch around the hula hoop to form what looks like an upside-down wizard's hat. This can be placed under a hanging bird cage and secured to the cage using zip-ties. Seed will fall into the table cloth, and the entire rig can be dumped during weekly cage cleanings.
Elastic Table Cloth
Another simple solution for a bird cage seed catcher is to use an outdoor plastic table cloth with elastic edges. These are typically slipped over outdoor patio tables, and the elastic holds the edges taut around the table to prevent wind from catching the cloth. These can be used as seed catchers by simply attaching them to the bottom of your cage, away from the bars so the birds cannot reach the plastic and potentially choke. Use plastic hangers between the elastic and the cage to stretch the elastic so the cloth is slightly outside of the cage, making room for seeds to fall and be caught.
Metal Oil Pan
Another option for catching seeds is to place a metal oil dripping pan from an automotive supply store underneath your cage. These are large metal sheets that resemble oversized baking trays. Placing your cage on or above the oil dripping pan will cause any seeds or shells that are thrown by the birds to be caught by the pan where they can be easily vacuum or swept up.
In order to prevent seeds and shells from being thrown from the cage, you need not cover the entire cage, you only have to shield the area from the bird food dish down. A simple solution is to stitch together a beach towel so that it fits snugly around the cage, and slide it up so that it covers the first few inches of the bottom of the cage. This can easily be removed for cleaning, and will allow air in to the cage when it is installed, while simultaneously keeping seed hulls inside where they can easily be cleaned up.