(But are they a sign of alien invasion - or just pesky humans having a laugh?)
Mysterious crop circles have appeared in farmers’ fields, sparking a police investigation.
Cops are trying to find out what - or who - is behind the series of strange circles in the wheat plantation in Chicoana, near Salta city in north Argentina.
Crop circle investigator Mercedes Casas said: “The pattern in this case is of nine circles that start big and get smaller as you move along.
“The first has a diameter of seven metres, then they get gradually smaller until the last one, which is four metres and has some peculiar markings.
“The circles are connected by lines about one metre wide and a few centimetres tall.”
And it’s not the first time either.
In February, there was another incident of markings of odd and unknown origin in fields in the same province.
Mercedes believes they are the work of ‘humanoids’ – extra-terrestrial beings in the form of humans, which she describes as “tall and blonde beings”.
But others suggest they are done by people as a prank. Surely not?
Professor of physics at Truman State University, Taner Edis, said: “All fall within the range of the sort of thing done in hoaxes.
“Although obscure natural causes or alien origins of crop circles are suggested by fringe theorists, there is no scientific evidence for such explanations, and human causes are consistent for all crop circles.”
How can he be so sceptical, eh?
(All images: Caters)