Aaron Balick expected to find a tiny mouse rustling behind the TV in his apartment. Instead, he found a venomous giant centipede that somehow hitched a ride from South America (search) to Britain (search).

"Thinking it was a mouse, I went to investigate the sound. The sound was coming from under some papers which I lifted, expecting to see the mouse scamper away," the 32-year-old psychotherapist said Wednesday. "Instead, when I lifted the papers, I saw this prehistoric looking animal skitter away behind a stack of books."

He trapped the 9-inch-long creature between a stack of books and put it in a plastic container.

The next day he took it to Britain's Natural History Museum, which identified the insect as a Scolopendra gigantea (search) — the world's biggest species of centipede.

Stuart Hine, an entomologist at the museum, said it was likely the centipede hitched a ride aboard a freighter, likely with a shipment of fruit.

"Dealing with over 4,000 public and commercial inquiries every year, we have come to expect the unexpected. However, when Aaron produced this beast from his bag I was staggered," Hine said. "Not even I expected to be presented with this."

The Scolopendra gigantea has front claws that are adapted to deliver venom when it stings, which can lead to a blistering rash, nausea and fever. The sting is rarely life-threatening, but painful.