I think you mean Brownian movement. In theory, they're supposed to, depending on the animal. Like Shayne said, about ants, it's a chemical trail. Look thought at 'flyers' and 'gliders' (like flying squirrels, even snakes); they have a trajectory, like automatic trigonometry and they account for this in their travel.
Plus, there's the topography - the key! What is straight is the surface is not? Changes the whole dynamics.
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The ones who say “You can’t” and “You won’t” are probably the ones scared that you will. - Unknown