Mysterious Horses in Central Illinois

There's not much to see in Fairbury, Illinois, with one notable exception. About three miles west of town, you'll find a row of about 20 bouncy horses. In the summer when the corn is high, they're hard to spot from the road, but in late October they're the only break in miles and miles of corn fields. Are they an art installation? Teenage prank? It's unclear, but the horses allegedly appeared one by one under cover of night.