The answer to 'why is my bee swarms' is that bee swarms are a natural process where a colony of honey bees divides and a new queen bee leads a portion of the colony to a new location. This typically happens in the spring as the bee colony grows and the old queen leaves with a portion of the worker bees to establish a new hive.
Bee swarms are not typically aggressive, as the bees are focused on finding a new home rather than defending their colony. However, swarms can be a nuisance and may pose a risk to pets or children. It's important to avoid disturbing the swarm and to call a professional pest control or beekeeping expert to safely remove the swarm if it's located in an inconvenient or dangerous area.