A bottle cap for fitting on a mouth of a bottle to form a bird feeder is disclosed. The bottle cap comprises a first chamber with a opening for receiving the mouth of the bottle, wherein the bottle cap snaps onto the mouth of the bottle. A second chamber is provided with a closed bottom. A sealing ring is located between the first and second chambers so as to provide a seal between the bottle cap and the mouth of the bottle when the bottle cap is snapped onto the mouth of the bottle, wherein liquid is free to move between the first and second chambers. At least one feeding port is provided in a side wall of the second chamber.