People often set those humming bird feeders out for them, and from what i’ve read they can be potentially harmful if not cleaned out regularly (every other day). There are some brands of nectar that also have dyes that are toxic to the hummingbirds (and people).
I’ve heard that a preferred method is to grow plants/flowers that hummingbirds like. Seems like a lower maintenance method, but if you do decide to have a feeder clean it often please 
