Based on the information present in the given passage, you need to write a correct answer to the given question. A correct answer is one that correctly and completely answers the question. Do not write answers that address the question partially or incorrectly. The correct answer must be contained in the given paragraph.

Example input: Paragraph- Sent 1: Obama was born on August 4, 1961, at Kapiʻolani Maternity & Gynecological Hospital in Honolulu, Hawaii.
Sent 2: He is the only President to have been born in Hawaii.
Sent 3: He was born to a white mother and a black father.
Sent 4: His mother, Ann Dunham (1942-1995), was born in Wichita, Kansas, of mostly English descent, with some German, Irish, Scottish, Swiss, and Welsh ancestry. Question: How old was Obama's mother when he was born?
Example output: 19.
Example explanation: Obama was born in 1961. His mother was born in 1942 and 1961-1942=19. Therefore, any of the following responses are considred correct: '19' and 'almost twenty'.
Q: Paragraph- Sent 1: After his cousin Joe dies , Layne Vassimer and his girlfriend Macy , along with their friends Stephen , Maurice , Iris and Katrina , decide to clean up Joe's house with the intention of selling it .
Sent 2: When they see it for the first time , they discover the house completely covered in plates of iron armor .
Sent 3: The group also finds crop circles in the nearby cornfield .
Sent 4: When Iris , one of their friends , suddenly disappears they realize something is really wrong .
Sent 5: During a blackout , the house is attacked by aliens , who had previously killed Joe and abducted Iris .
Sent 6: The group figures out the aliens are allergic to iron , Joe had covered the house in it to keep them out .
Sent 7: They attempt to fight the aliens off , but the house is eventually blown up with Layne , Macy , and Katrina the only survivors .
Sent 8: In the end , they drive off , listening to the radio .
Sent 9: They hear a news report stating that the blackout they experienced affects five western states and parts of Canada .
Sent 10: They also hear that people everywhere are being attacked by `` strange creatures . ''. 
Question: What they find when they cleaned Joe's house?.
A:
They find crop circles in the nearby cornfield.