The answer to 'why is my bee droppings' is that what you are likely seeing is not bee droppings, but rather the byproduct of a honey bee colony. Honey bees produce a substance called 'bee poop' or 'bee frass' which is a combination of wax, pollen, and other materials that they excrete. This is a normal part of their hive activity and is not a sign of a problem.
Bee frass is usually found around the outside of a beehive or on surfaces near the hive. It appears as small, dark pellets or spots. While it may look unsightly, bee frass is not harmful and is simply a natural byproduct of the bees' activity. If the amount of bee frass seems excessive, it could indicate a larger hive that may need to be addressed, but otherwise it is not a cause for concern.