California: American Airlines confirmed a flight from California to Phoenix was canceled for an unusual reason—a scorpion was spotted on board the plane.

Airline spokeswoman Leslie Scott said the Boeing 737, which had been due to depart Sacramento at 10:40 am Sunday, had been in Phoenix the previous day, and that’s likely where the scorpion boarded.

Passenger Jim Zuber said he and more than 100 fellow passengers were told while waiting to board that the flight crew had spotted a scorpion on the plane and the airline was determining the best course of action.

The airline eventually decided to cancel the flight, reports UPI.

‘The flight was canceled because we want passengers and crews to feel comfortable,’ Scott told the Sacramento Bee.

‘This is one for the books. Or Believe it or not. American Airlines is canceling my flight because they found a ‘SCORPION’ in the plane!’ one traveler wrote on Facebook. ‘I suppose I should be happy it is not a BOMB!’

Scott said the plane was taken to a maintenance facility in the Dallas/Fort Worth area to be fumigated after the crew was unable to determine whether the scorpion was still aboard the flight.

Flight delays attributed to scorpions are rare, but not unheard of—an Ecuador-bound United Airlines flight out of Houston’s George BushIntercontinental Airport was delayed for several hours in May when a scorpion was purportedly seen crawling out from the sleeve of a sleeping passenger.