Several times a day, the robots paraded down the main street of the park, attacking each other with different weapons. Marge mentioned that they might be dangerous, but the guard told her that they aren't. They had sensors and programming that ensured that they would only attack each other and never attack visitors to the park.
Flash photography of the robots was forbidden. When Cletus took a photo of one, the robot sparkled and spoiled itself.
While repairing a destroyed robot in a special room, Professor Frink arrived there to tell mechanics about his chaos theory. It says that all robots would eventually attack their masters, but the park's robots wouldn't do so for at least 24 hours. However, his calculation was incorrect, because the robots attacked as soon as he finished his speech.
The robots started walking over the park and attacking every visitor they met. The employees quickly evacuated the guests. However, when the Simpson family wanted to board on the helicopter, they were left there, as Homer and Bart had attacked several employees before. The robots surrounded the family and Homer started throwing everything he found in his pockets at them. It didn't work until he threw his camera that took a photo of the nearest robot with flash. The robot was spoiled, so the family grabbed cameras and started photographing to destroy all the robots.
The family eventually won the fight and the owner of the park Roger Meyers, Jr. gave them two free passes for their stopping the killer robots.