Acquire a pre-cut clear acrylic window feeder housing or construct one using high-impact clear polycarbonate sheets joined with specialized acrylic solvent cement. Ensure the removable interior feed tray features fine laser-cut drainage slots across its entire base to promote rapid water runoff after rain showers. Thoroughly clean the targeted exterior window glass surface using a mixture of isopropyl alcohol and water to remove all dirt, oil films, and grime residue. Moisten the rubber seals of three or four heavy-duty industrial suction cups mounted on the back panel of the acrylic feeder housing. Press the suction cups firmly against the prepared window glass, squeezing out all trapped air bubbles before sliding the seed-filled tray insert into the secured housing channel.