Bees will form a cluster on the outside and given time make their way into these voids. It only takes 24hrs for the honeybees to start making their wax to put their honey in. Honeybee nests and hives usually go unnoticed for months before they are discovered. In these cases other pests become attracted to the smell of the honey such as roaches and ants. Honeybees (EHB) will normally swarm at least 2 times a year moving to a new place nearby as the original hive continues to prosper. There is of course a small percentage of bee hives that die when the queen leaves them behind. There is however a greater percentage of these empty hives get re-colonized by new swarms leaving their hive nearby. The wax that was built along with all sweet smelling honey attracts the bees to move in. Household sprays do not work effectively, only it caused the honeybees to go in defense mode where they could potentially attack. African bees (AHB) will do exactly what European (EHB) bees do, only sooner and in larger numbers. I've seen where yellow foam was used in attempt to seal the bees in causing even more problems. Sometimes it works and runs all the bees into the house or out some other opening. When it doesn't work it becomes more of an obstacle when the beekeeper comes to try and remove them. Licensed pest control applicators are sometimes necessary to control the flight of the bees so they do not give chase to children and pets that may be nearby. Whether or not pesticides are used it is always necessary to remove all the honey so migrating bees don't move back in later. There are some cases where honey removal is not recommended like in block walls. Breaking the cement blocks to get the honey out could bring the whole structure down. Beehives are easily removed from drywall, stucco and wood. Leaving dead bees inside your wall, ceiling or floor will create a rancid odor as they decompose. This smell usually cannot be detected from block structures. Hive Beetles have been seen in most hives removed from wall voids and ceilings where they have been there a long time. Hive Beetles feed on the stored pollen and honey often ruining the colony. Sealing a beehive in that is infested by hive beetles will force the Hive Beetles into your home.