Why are bees all over my Hummingbird feeder
What could be a fault of your own as bees may be attracted to your hummingbird feeder do to nectar being made available on the exterior.
Why bees are all over your hummingbird feeder is because it can appear to be a real nectar flower, to which they feed off in the wild. If this feeder is swarmed over by many, it could be nectar is accessible, via the port wells or with sugar over the exterior body. Unless the feeder is kept clean, bees will continue.
No hummingbird feeder is safe, as swarming bees or fewer can come and go, more so if nectar remains accessible, but less so if nectar is tightly bottled away.
I will say even the best bee proof hummingbird feeder can't stop them being over your hummingbird feeder, or through a bee guard attachment can help if the nectar is indeed accessible on the exterior.
Could be because pools of nectar are on the part wells, due to a feeder fault or hummers making a mess - and so to can sugar water be over the body of the feeder - as it gets stepped on by hummingbirds, or similar nectar attracting birds that spread it around.
Hummingbird feeders do attract bees with nothing much you can do about it, with feeders made to look like the nectar flowers, bees are naturally attracted to in the wild.
Odor can be sure bees remain on the hummingbird feeder, but with the issue of swarming bumblebees persisting - it could because bees are successfully feeding off nectar somewhere or another.
How you would get bees off a hummingbird feeder is by cleaning up the feeder with clean room temperature water; to wash the exterior body of its sticky nectar, whilst removing pools of trapped nectar in the wells.
Bees are over your hummingbird feeder because they can smell nectar in the air, but its likely these same bees are feeding off nectar that is exposed on the outside.
Bees are attracted to sweet nectar
Why you may be finding your particular hummingbird feeder to be swarmed by bees, is of course because bees can detect nectar in the bottle.
And where nectar is secured tightly in this contraption, bees may be found all of a feeder if its one that looks like a nectar flower by sight, to which is how birds find nectar, with sight or smell.
Bees therefore can be found crawling all over a hummingbird feeder in large numbers as they find a way to feed off... what they can't actually access most of the time.
While that can be true under most circumstances, of course the sweet smell of sugary-water locked behind a plastic or glass bottle will see bees continue to swarm knowing nectar is within reach.
Bees are attracted to nectar within feeders in just the same way in the wild, as they notice nectar flowers - then proceed to feed on it due to the nectar odor in the air.
Whilst hummingbird feeders can do a good job at keeping nectar within, there's no telling how much nectar is exposed on the outside.
Well ports accessible
As bumblebees continue to swarm a hummingbird feeder for the availability of nectar they know is close by, nectar can be constantly exposed in the open via the well ports.
Well ports can be a single one or several where hummingbirds poke their beak in to sip on the sweet nectar within the feeder.
Over the course of the day drops of this sugar water will be available outside of the feeder, to which will allow bees to access it unimpeded.
And that is another reason why bees are swarming your hummingbird feeders, because your homemade nectar is out in the open.
Not much can be done to keep this area clear of nectar, but it won't hurt once in a while to splash it with room temperature water to wash off the nectar - only when hummers have disappeared for a while.
Result of nectar available at these port wells is bees become a nuisance to hummers, as bees can block off this feeding port, which hummers won't use as bees are all over it.
Familiarize yourself with what is a bee guard fixed to these well ports, to prevent bees access the nectar, while only reserving the nectar for hummingbirds.
Feeder body caked in sugar
Why bees are swarming over your hummingbird feeder is due to the nectar only, so therefore the sugar water available all over the body of the feeder can be trouble.
Over the course of the day, or at least until you clean your hummingbird feeder again, hummers will proceed to spread nectar which would be stepped on, then continued to be spread mostly around the exterior body.
Body being the disk or section where the perches are usually positioned, whereas the bottle or container that holds the nectar remains clear.
Hummingbird feeder bodies can be caked in sugar within hours of use, with the problem of bees over it getting worse.
What you must to do is wash the hummingbird feeder exterior as often as you can, to keep it clear of sweet smelling nectar.
Wait until all hummers have left the feeder before splashing room temperature water over it; no soap or disinfectant, just clean water in a bucket - with a garden hose or pressure washer used to speed up the process, if available.
Clean a hummingbird feeder like this as regularly as you can to prevent a more sticky, hard to remove residue forming on the exterior.
Fault of unkempt feeder
Bees are all over your hummingbird feeder because most of the time, the nectar that should be in the inside, is exposed on the outer body or port wells.
Its therefore possible bees are swarming in large numbers to actually try and feed on what is homemade nectar similar to what they feed on in nature.
How to get rid of bees on a hummingbird feeder is to keep the feeder maintained, to avoid any of the sugar standing on the exterior. Similarly, you'll need to do this to stop your Oriole feeder being attracted by bees, if nectar is exposed also.
Unkempt hummingbird feeders are therefore the cause, thus a regular clean can keep bees well away.
I must tell you hummingbird feeders must be cleaned once a week, or two or three times when nectar is seen to spoil far sooner in the heat or in cold conditions.
When you've cleaned the hummingbird feeder, you'll need to hang it back up carefully as a hummingbird feeder not balanced upright will see nectar spill ever so slightly, as a feeder on an angle can cause spillages.
If these small spillages are not cleaned up with water right away, the port wells will have pools of accessible nectar for bees, with the body once again covered in nectar.
To summarize
Why are bees swarming your hummingbird feeder can be for a couple of reasons, with the most likely outcome being nectar is available on the exterior, rather than stored away.
Bees are attracted to hummingbird feeders because these feeders can look like nectar flowers, which could be why bumblebees are a attracted to it in the first place. On top of that, the smell of sweet nectar odor will be in the air.
Well ports, which is the area hummers feed off, would usually trap pools of nectar that is exposed to the bees - thus the nectar is both accessible with the small around the feeder attracting bees to it.
Hummers can tread nectar over the hummingbird feeder in a way bees can be forced to swarm over, without really accessing any your homemade nectar.
Nectar must be in drip form at the minimum for bees to successfully feed on, while a bee guard attachment at each port well can prevent them.
Bees swarming a hummingbird feeder lays at your feet, unkempt hummingbird feeders can attract bees if the nectar is allowed to remain on the outside; with stepped on nectar of the body exterior, or pools of nectar filling up on the wells.
What you must do to prevent bees over your feeder is to clean the hummingbird feeder regularly, together with a quick splash of cool water over the body once or twice a day to clean off accessible nectar.