Use a wire cutter to cut the wire coat hanger below the twisted portion and discard the twisted portion and the hook.
Hold the middle part of the wire against the middle of the side of the mayonnaise jar. Bend it around the bottle so that one end forms a loop around the mouth of the jar and the end hangs over the center of the jar opening. This forms a perch for the hummingbird.
Bend the other half of the wire around the jar once. Straighten the remaining portion so that it extends past the bottom of the mayonnaise jar. Form a hook at the end to serve as the hanger.
Drill one 1/8-inch hole in the center of the jar cap. The hummingbird will drink the artificial nectar through this hole.
Fill the mayonnaise jar about three-quarters full with artificial nectar. Hang the feeder upside down at a slight angle so the hummingbird can comfortably perch on the wire end over the bottle mouth. Locate the feeder where you can easily view it.