Most security and insurance experts agree that burglaries tend to increase during July and August when it stays for daylight longer, when most people go on vacation. Burglars know the signs that let them know a family isn't at home: a porch light left on all day, newspapers piling up in the driveway or a mailbox that is stuffed full, said Chris McGoey, a longtime security consultant, trainer and speaker. Those are some of the more obvious signs. But there are things burglars look for that may not be so obvious. Leaving the blinds closed so nobody can see in while you're away is a double-edged sword, said McGoey, who also runs a security-education Web site called Crime Doctors. While a potential burglar can't see your valuables, closed blinds and curtains are also a sign that tells him no one is home.