The bottom-fill hummingbird feeders include a traditional bottom-fill feeder and several variations of it. The traditional ones are filled from an opening at the bottom of the nectar container but many manufacturers have come up with improved variations of the traditional style of feeder, to make feeding birds easier and with less nectar wasted. Some bottom-fill feeders come with a funnel-like opening at the bottom of the container, through which the feeder is filled. Other bottom-filled hummingbird feeders can be attached to one's window to provide a close-up of the birds.