The team says that the ants' headings during accelerating and decelerating moons fit a kind of linear extrapolation prediction rule. The ants predict the moon's movement by combining linear extrapolation with a rapid "speed-step" when the moon is at its highest point in the sky—its lunar apex. However, they also found that errors in the ants' prediction peak around the speed-step due to night-to-night variability in the moon's arc. Still, these are apparently sophisticated navigation abilities, showing parallels to human-made navigation systems.