I have to leave my front door unlocked for my big children to get in (they would lose a key each!) between about 3.45 and 4.20 after school -they walk home-the rest of the time it is locked or on safety chain, parent seemed to have caught onto this and are letting themselves into my house without knocking, just walking in even when my dh was in kitchen a parent had let themselves in and walked past him saying just passing through! Is this normal or should I do something about it..... Been cming for years and never really had it before?