The 3 louvered crawlspace vents like the one pictured are often found damaged and their screens missing from small animals that can easily separate the louvers and enter the crawlspace. It is recommended that this type of vent be removed and replaced with a grid or grille type screening with sliding vents. Small animals can do costly damage to the HVAC ducts and flooring insulation as well as other damage. Spring Hill TN_Louvered Crawlspace Vents