This is certainly terrifying for anyone who has a pet door.

You sometimes hear about unexpected guests such as squirrels or raccoons who may come through your pet door and suddenly appear in your kitchen. Unfortunately for one New York man, the intruder in his home happened to be human.

NYupsate is reporting that a 21 year-old man from Macedon, NY fought off a burglar who came crawling through his home's doggy door. WHAM reports that Levi Thompson was awoken to sound the of someone going through his stuff in his bedroom. One of the items the unwanted guest took was a pocket knife.

Thompson told WHAM that when he told the intruder (a former friend of his) to empty his pockets, the other man pulled the knife and held it to Thompson's throat. The terrified young man then punched the assailant with his free hand to break loose, only to see the other man wack him over the head with a 30 inch decorative wooden post. 

The suspect escaped out the same doggy door, only to be arrested in an unrelated traffic stop, according to police.

WHAM says the victim suffered a fracture skull and bleeding on the brain, but is expected to recover.

Police say one of the reasons the 19 year-old intruder was able to squeeze through such a small space was because he was very skinny.