Cells wander, biased up the gradient of a chemical that they themselves release. The chemical diffuses and decays. The seed sets the strength of the pull χ.
Tap to scatter a clump. The same ?seed= always gives the same run.
LITA discrete Keller–Segel chemotaxis model. The chemical must stay non-negative and every cell must stay in the dish, or the page throws.
AMBERThe mound count depends on χ and the grid; it is not fitted to a real organism.