Why are raccoons sometimes considered pests in our society?

because they can scratch and Bite

Raccoons often get into trash and scatter it about. They can cause a lot of damage to roofs and attics. They raid our gardens and fields for food. Raccoons will eat food we have left out for our pets. They can carry rabies and a number of other diseases that can be transmitted to humans. Their feces can carry eggs of a round worm that can infect humans and pets and cause a fatal disease.