To seal attic entry points, begin by inspecting the attic thoroughly for cracks, gaps, or holes in walls, floors, and the roof. Pay special attention to areas around vents, chimneys, and where building materials meet. Use high-quality silicone or polyurethane caulk to fill small cracks and gaps. For larger openings, especially around pipes or wiring, fill them with steel wool or copper mesh before applying caulk to prevent pests from gnawing through. Cover vents and chimneys with fine metal mesh to maintain airflow while keeping pests out. Ensure the mesh is securely fastened and free of damage. Additionally, trim tree branches and vegetation away from the roofline to reduce access points for pests and regularly inspect and repair any exterior damage.