Possible Clues:

• Left the top off timepiece - it's crucial for getting into the internal housing
• Sadly, they lack an opener
• Lecturer at church has code which unlocks the door
• Tail up having dismissed one companion - important opener
• Means of entry to (parentless?) house
• Door opener
• Common device to open outer door
• Sort of self-reliant child they lack, unfortunately
• Child who regularly returns to an empty house
• Such a child has only this present to open