If rainwater infiltrates attic vents, it can lead to severe structural damage. The moisture can seep into the insulation and framing, causing mold and rot. The weight of the saturated insulation can also strain the roofing system, potentially leading to collapse. Furthermore, the damp conditions can attract pests and create an unhealthy living environment. Proper attic ventilation is crucial to prevent these issues and ensure the longevity and well-being of the home.