Dots and Circles

I am really enjoying creating animations using nodes, but am having problems figuring out creating complex circle or dots. Below are the two ways i have found that are not very complex.
For example being able to position dots in a particular area and get them to grow and interact.
Getting cells to multiply or morph into an other shape.
What suggestions does any one have? Maybe a location node that i don’t know about.


Voronoi texture

Spherical Gradient

Here are examples of some animations i have bed working on.