Ant Odometer
Ants "count" their steps. When they find food away from their ant hill, they walk back. But if the ant's legs are longer, they walk past their ant hill and keep going. If their legs are shortened, they will not walk far enough.In conclusion, the ants will "follow their footsteps" back to their ant hill.
Cellular Automata
Cellular atomata are a class of simple mathematical systems that can model a variety of physical processes with complex behaviors such as forest fires, the spread of the plant species, the oscillations of chemical reactions, and propagation of animals such as barnacles.