Crawlspace entrances are your first defense against bugs, dust, rodents and other allergens and asthma triggers. This entrance doesn't do much to stop anything. Dr. Energy Saver recommends replacing this entrance type with a Turtl®. Turtl's® offer a safe entrance into your crawlspace that most people can easily enter and exit through; a tight seal that keeps bugs, rodents and dust from entering; and the Turtl® also offers the opportunity to put a lock on the crawlspace for added security against unwanted visitors.