Simulation code in C for stigmergic avoiding animals

The C code contained here simulates the collective movement and interaction of animals in a 2D lattice as follows. Each individual moves as a random walker (with different type of movement statistics) and deposits a mark over each of the lattice location it visits. The deposited mark remains present only for a finite amount of time, T, after which it disappears. When another individual encounters a foreign mark, it retreats towards the centroid of its own active marked area with a probability that decreases as a function of the age of the mark. The functional form with which it decays is controlled by the response decay exponent. For more details read the Material and Methods and Supplementary Information of the article.