A 5.5-metre-long snake has been seen slithering across the roof of a US home, spooking neighbours and leaving many wondering how it had come to be there.

Key points: The snake's owner said it had gone onto the roof of his garage to avoid dogs

The snake's owner said it had gone onto the roof of his garage to avoid dogs He said it was his fault the snake was out of its cage, which he had forgotten to lock

He said it was his fault the snake was out of its cage, which he had forgotten to lock The snake has lived in captivity its whole life and had never harmed a human

"Oh my god it's moving and it's huge," neighbour Latonda Harvey said in a clip posted to social media.

"You see that!

"I'm going to need a drink after this, this is some bullshit."

The massive eight-year-old reticulated python, called Juliet, drew quite a crowd as it made its way slowly across the tiles of the Detroit roof.

Police came to check it out too, with officers taking out their phones to record the spectacle.

"She's about 18 feet long, 18-plus feet, so I can understand people worried about seeing a big snake sitting on top of a garage like that," owner Devin Jones-White told Detroit's WXYZ.

"It was my fault that she did get out.

A few minutes into the video, a man appears on the roof and drags the snake down. ( Facebook: Latonda Harvey )

"[I] didn't put the lock on probably. I was able to get here, get her back to her cage quick."

He said he could understand people being worried at seeing such a massive snake on the roof.

"But she's not going to do anything to a person," he said.

"She's never harmed anyone, I got her from an older couple. She doesn't really know anything about the wild."

Juliet had probably scaled the garage to avoid dogs, Mr Jones-White said.

During her video, Ms Harvey repeatedly remarks about the snake's stomach and speculates that it had recently eaten.

"Something is up inside of it," she said.

Mr Jones-White said Juliet mainly ate thawed rabbits.

A man off-camera tells Ms Harvey the owner of the snake has "some kind of pet store" and sometimes keeps animals, including roosters and puppies, in their house and garage.

"Welcome to the neighbourhood," he said.

"They got all kinds of stuff in there."

After Juliet had been on the roof for about ten minutes, Mr Jones-White appeared and grabbed the slow-moving snake with one arm, initially struggling to pick it up before moving it to the edge of the roof and dangling part of it off.

In his efforts to remove Juliet he fell to the ground, recovered and let the snake use him to climb down the ground.

By this time a large crowd is watching, many with phones raised and grins across their faces.