Question

Are there occasion when the beads converge then expand

Answer 1

The adjustment in temperature causes this extension. The expansion in temperature makes the droplet to extend and diminish in temperature brings about the merging on the dots. 
When you will warm the droplet then dabs will grow and in the event that you diminish the temperature, on the other hand, they will meet.

Answer 2

The change can occur due to lowering of temperature or increase in temperature. Thermal expansion can be seen in all states of matter, i.e. solid, liquid and gas. When the temperature rises, beads would expand. They would again converge is the temperature drops.