Intro: BIRD FEEDER - FOR APARTMENT WINDOWS
this feeder is designed for apartments with little or no ledge space.. and ideally with metal grills. this design would also work well in a garden or any other setting.
You will need :
1) a plastic bottle
2) a pair of scisors
3) twine or thin rope
thanks to @l8nite for this tip : "as with any bird feeder you have to be sure to check the feeder after it rains, clean and dry it to prevent mildew or rotting seeds"