First is honeybee swarms. Annually, as in right at this moment, honeybee colonies split off small groups of workers and new queens, and these swarms leave the parent colony to locate a new nest site. Quite often homeowners are terrified by a volleyball-size blob of bees in a shrub in their yard, and they want them killed. Given the plight of honeybees at this time with Colony Collapse Disorder, it would be negligent of us to kill all these honeybees. Instead, try to educate the customer to understand why the bees are there, the extremely low potential for them to sting at this time, and that they will leave on their own within a day or two. They simply are resting there while scouts go looking for a new home. However, if the bees are seen entering and leaving the structure itself, particularly if they are carrying pollen in, it suggests there now is an established hive within the structure, and if a local beekeeper will not remove them they need to be killed. This can be done with an insecticide injected into the entry hole or directly into the void they are occupying. 

Another call that is coming in commonly right now is for "burrowing" bees of several kinds. These will nearly always be solitary bees that pose no threat of stinging except for that odd circumstance when someone grabs a bee and holds it in their hand. Solitary bees are not protecting a hive or colony and have no instinct to sting except in self defense. And, nearly all of those little bees people see hovering and swirling around over the ground are male bees that cannot sting. The females are too busy digging the tunnels and chambers in the soil, laying eggs, and gathering food supplies for their offspring. These bees should definitely be left alone and enjoyed for the benefit they provide in pollination. 

Honeybees in the landscape that are gathering pollen or nectar from flowers also pose nearly no stinging threat. They often gather at muddy and other wet areas to gather moisture, and the control there could be to allow that area to dry up, removing the attraction. But, foraging bees are not interested in people nearby, and would not sting unless directly provoked. I know you will have plenty of customers who will listen to all of this and still say "I don't care. I want them killed. I'm allergic to bee stings. Etc." However, trying to kill all of the bees flying around in a yard would be tough to do, and instead suggest to the customer that they make some changes in their landscape, such as removing shrubs and flowers that are highly attractive to bees and replacing them with equally attractive plants that do not offer the nectar or pollen that bees want.