Thousands of live earthworms have been falling from the sky in Norway - a rare phenomenon being reported across large swathes of the south of the country. A biology teacher discovered the worms on the surface of the snow while he was skiing in the mountains near Bergen at the weekend. Numerous reports have been coming in after he told his story, and there have been sightings of worm rainfall. Worm rainfall: Karstein Erstad took this photograph of the worms he discovered in the snow on Sunday . Teacher Karstein Erstad told Norwegian news website The Local: 'When I found them on the snow they seemed to be dead, but when I put them in my hand I found that they were alive.' Initially he thought they had wiggled their way through the snow, but dismissed this when he realised it was up to a metre deep in some places. Following Mr Erstad's discovery on Sunday, there have been similar reports in southern Norway and sightings of worm rainfall in Lindås and Suldal near Bergen, and also hundreds of miles away in Femunden. The biology teacher told The Local: 'It’s a very rare phenomenon. 'It’s difficult to say how many times it happens, but it has only been reported a very few times.' After Mr Erstad found the worms on Sunday, there have been multiple reports or worm rainfall in Norway . He said he found reports of the same strange phenomenon taking place in Sweden in the 1920s. In 2011, a group of pupils playing football at a school in Scotland witnessed worms falling from the sky. The students at Galashiels Academy in Selkirkshire had to abandon their game when the invertebrates began falling on them. According to the Mother Nature Network, some incidents of creatures falling from the sky have taken place after tornadoes and storms and scientists think they could have been picked up and carried for miles.
Teacher Karstein Erstad found thousands of live worms on top of the snow.
There have been  reports of worm rainfall in Norway following his report.
Mr Erstad says the 'very rare phenomenon' happened in Sweden in 1920s.