Yes, call the nearest beekeeper association, or 'farmer' or whoever to come and do the job because bees are in very short supply lately and it's wrong to kill them if there's any way around it. Professionals will lead the queen (and all others will follow her) to a new location.

Bees staining aluminum siding? How?

Are you sure that they are bees ? I have an eighty year old cottage where I battle with wasps every year, could that be your problem ? If so, a trip to the hardware store will get you a spray that will solve it, but make sure that they aren't bees first , and then MAKE SURE YOU READ THE DIRECTIONS ON THE CAN !

What do the nests look like? My guess is they are the ever-present paper wasps, which drive me crazy year after year and for which I am constantly knocking down nests built in eaves and doorways. These are supposedly beneficial insects, but I wish they wouldn't build their nests in places of egress. They aren't honeybees, which is what I suspect larke was worried about when he/she suggested contacting a beekeeper.

Lastly, why do you think they will stain your siding?

I believe she is looking for a treatment that won't stain VINYL siding...

Honeybees or wasps?

A decent stream from a garden hose nozzle can usually knock the smaller wasp nests off the house.

Do it in the evening (twilight, not by the clock) when they are less active 9some may cling to the fallen nest and be more than willing to go after you).

A can of insecticide for any remaining on the nest on the ground will finish them off.

Actual honeybees find a beekeeper.

They are normally not that aggressive and can be smoked and safely moved.