The answer to 'why do I have wasp' is that wasps are attracted to your home for a few common reasons. Wasps are looking for sources of food, shelter, and materials to build their nests. They may be drawn to sweet smells from trash, pet food, or ripe fruit, or they may be constructing a nest under the eaves of your home or in a tree on your property.
Seeing wasps around your home is a sign that you have an active nest nearby. Wasps can become aggressive if their nest is threatened, so it's important to address the issue safely, either through DIY methods or by calling a professional pest control service.