DES MOINES, Iowa (AP) — Some wayward ticks delayed a United Airlines flight from Denver to Des Moines.

Flight 1178 was delayed for nearly six hours on Tuesday after a passenger informed a flight attendant that she found a tick in economy class during a flight from Washington, D.C., to Denver.

The airline decided it couldn't fly the plane until it was cleaned of ticks, so passengers had to wait while another plane was flown from Colorado Springs to Denver. The flight was further delayed because of thunderstorms in the Denver area.