Mantis was originally designed to run three trains on its course. However, the complex trains have caused the loading times to be longer than anticipated. This caused the trains to "stack" on the brake runs. Stacking refers to guests waiting outside of the station on the brakes while waiting for a train to leave the station. To correct this problem, Mantis now runs only two trains, allowing quicker loading times. The other train is stored in the maintenance bay next to the ride, visible from the queue.