"And you get a gold star, Riverbee. They were made in Poteet, Texas."
these are probably the best hummer feeders made on the market. simple,durable, well constructed and they do not leak.
you don't need to purchase guards for them, or swap them out. if you have some avon skin so soft, take a cotton ball, soak some skin so soft on the cotton ball, swab it around the ports of the feeder. it will keep all stinging insects off, including ants, and won't affect or hurt the hummers, reapply as needed. if you don't have any find an avon lady or amazon carries it, i think. this stuff also keeps skeeters and gnats off of me.
keith is correct about the 'nectar source'. you might have a conversation with your neighbor wm, and maybe help him/her out.