And police are completely baffled as to why.
If you thought you'd seen and heard it all, then brace yourself for this.
Because police from Salinas, California, USA have released one of the most bizarre video's you'll ever see.
The security footage, recorded on a doorbell cam, clearly shows a man trespassing outside of a family home, before he begins licking the doorbell.
Yes...you read that correctly.
Police in California have identified the 'licker' as 33-year-old Roberto Daniel Arroyo.
As for his motives? No one is quite sure...
A spokesperson for the Salina Police Department told ABC7: "We were pleasantly surprised the image was so clear, it didn't take us long to identify the individual."
WTF. Image Youtube.Arroyo is thought to have spent a total of three hours outside the front of the house on New Year's Eve.
He was also filmed urinating on the property.
The property he trespassed on belongs to the Dungan family.
The parents of the family were out at the time of the...licking incident, however their children were sleeping inside.
It was the children who saw the CCTV footage and later called the police.
Sylvia Dungan was left feeling concerned by the experience - but admitted she was relieved things didn't get any worse on the night.
She told KION: "You kind of laugh about it afterwards because, technically, he didn't harm anybody, he didn't break anything."
Still, you would be fairly alarmed it you came across someone doing this to your doorbell.
Police say the suspect could face two misdemeanor charges when found for petty theft and prowling.
