Will the feeder attract ants, mosquitos, squirrels, etc.?
Ants most likely, and more problematically, yellowjackets if it has yellow on it. Yellow attracts yellowjackets, hummers are attracted to red. There's no reason to have yellow on a feeder but the feedermongers make 'em that way for us, thinking it's cute. Best to rip off those fake yellow plastic flowers if you can.
If you do get yellowjackets, move the feeder to another location. Yellowjackets are kinda stupid and the hummers will figure out the new location first.
You can keep the ants down by keeping it refreshed often (you'll often find drowned ants inside when you clean it out) and making sure it's not dripping.