Ananova:

Pulsating blobs filmed in a North Carolina sewer prompting speculation they were an 'alien' lifeform have been identified as worms.

The slimy sacs were filmed clinging to the crevices of a sewer and shying away from the light as a camera was passed along the pipes.

Footage of the creatures was posted on YouTube leading to speculation that an alien creature was living in the sewers of Raleigh, reports the Daily Telegraph.

The clip has attracted more than four million hits but now biolgists have confirmed the blobs are a colony of worms coiled together.

Ed Buchan, environmental coordinator at the Raleigh Public Utilities Department, confirmed the 'creature' was actually a colony of worms.

The colonies attach themselves to roots that gradually work themselves into weak points in the pipes.

"They seem to respond to the light from the camera," he said. "That light is pretty hot."

The film was made by a construction firm which had been contracted to carry out a survey of the state of the sewer system.

"We were asked by our client to inspect the sewer lines, which were built in 1949," a spokeswoman from Malphrus Construction said.

"Because the sewers are so old there were many infrastructure issues."