A chimney cap is a protective cover placed on top of a chimney. Its primary purpose is to prevent rain, snow, and debris from entering the chimney, which can cause damage and blockages. Additionally, chimney caps help keep animals, like birds and squirrels, from nesting inside the chimney. Chimney caps are typically made from materials like stainless steel, copper, or aluminum. They often feature a mesh screen to allow smoke to escape while keeping out unwanted pests. Installing a chimney cap can enhance the efficiency of a fireplace and reduce the risk of chimney fires by preventing sparks from escaping into the surrounding area.