Rinse the bottle in hot, running water. Pour a mixture of one tablespoon dish-washing detergent and one cup of water in the bottle and use a bottle brush to scrub the inside surface. Rinse the bottle again to remove any soap residue. Dry the bottle with a cloth or paper napkin.
Measure 4 inches from the bottom of the bottle and mark the point. Use a bottle lid with a diameter of 2 to 4 inches to trace two circles onto the bottle. The two circles start 4 inches from the bottom of the bottle and are on opposite sides of the bottle.
Cut out the circles with a pen knife. Use a nail or a paper punch to make a hole about two inches below each circle.
Insert the small dowel through the two small holes so that it juts out of two sides of the bottle, making two perches.
Poke two tiny holes in opposite sides of the neck of the bottle using a nail.
Remove the hook and the twisted part of the wire coat hanger so you get the triangular part. Push one end of the wire through the two holes in the neck of the bottle. Twist the part of the wire above the mouth of the bottle and bend the end to form a hook.
Make five holes in the lowest parts of the bottom of the bottle for water to drain out. Use a nail so the holes will be small enough to prevent the seeds from falling out.
Fill the feeder with seeds up to the level of the large holes. Hang the feeder in a tree or shrub where you can easily observe it.