It might not have been one of the signs of the apocalypse or even one of Moses’ 10 plagues of Egypt, but it probably should have been – eels with rows of sharp, jagged teeth have literally been falling from the sky on to an Alaskan town.

Residents of Fairbanks have been left scratching their heads, bewildered (and slightly terrified) by the fact that it is raining lamprey eels. The slender fish have been found on people’s lawns and in car parks, but where are they coming from?

The lamprey eel is not easily caught in Alaska, nor is it commercially sold, so these are not easy fish to get your hands on. Not that you would want to get your hands on them either; as you can see from the picture, these are more like something you would find in a science fiction film rather than a character from Finding Nemo.

Dubbed “vampire fish” and “fish monsters” by locals, there have been numerous theories as to how the eels have ended up on land. One theory is that waterspouts or tornadoes crossing over a lake or river can pick up debris, including light aquatic animals, and carry them for miles before they rain down. But no such weather system has been recorded, so this seems more likely to just be a load of hot air.

Others have said it is a practical joke. But no one person or group has been targeted, nor has anyone claimed credit for this weird prank, so that seems unlikely.

The most credible theory is that birds have begun preying on the lamprey eel – they can sometimes be seen picking the fish out of water and flying away with them in their beak. Occasionally they will drop their meal (or realise how unappetising the creature is) leaving them flopping on the earth.

Whatever the theory, it’s probably best for you to go right ahead and scratch Fairbanks off your list of potential holiday destinations this summer.