For this sketch, I used particles to simulate fireflies.
In the class of Particle, there is a constructor that generates objects based on the mouse position, a display method to display all the objects, a move function to move them, and a wind function to make them shake a bit when the mouse is pressed.
I used the model of the snow but changed the larger ellipse to yellow and the smaller ellipse to green. Also, in the display function, I used a random function to make the fireflies twinkle.
Everything begins with a single click. Then there will be fireflies generated as the mouse moves. And if the mouse is pressed, all of the fireflies will begin to shake.