In bed early Christmas morning, a North Carolina couple awoke to the sound of banging.

In a panic, they hid in a closet and called 911 to report a possible home invasion.

Forsyth County deputies arrived within minutes and found the culprit: a robot vacuum.

"They asked me how long I had it, and I said, 'About two days.' And they all just started laughing,'" homeowner Thomas Milam told WGHP-TV.

The vacuum had somehow turned itself on, gotten stuck and repeatedly crashed against a wall. The couple got it as a gift and named it Harry.

The Milams said they were embarrassed but glad they called police, just in case.