# snowflake fall blocks activity design a blinking rectangle animation. ## ~avatar avatar Welcome! This tutorial will teach how design a **snowfall animation**. Let's get started! ## ~ Let's start by creating a `forever` loop that will allow us to repeat the show LEDs code. Any code in the `forever` loop will repeat in the background... forever. ```blocks basic.forever(() => { basic.showLeds(` . . . . . . . # . . . # # # . . . # . . . . . . . `) basic.showLeds(` . . . . . . . . . . . . . . . . . . . . . . . . . `) }) ``` The next step is to add two `show LEDs` blocks inside the `forever` loop to repeat an animation. ```blocks basic.forever(() => { basic.showLeds(` . . . . . . . # . . . # # # . . . # . . . . . . . `) basic.showLeds(` . . # . . . # . # . # . . . # . # . # . . . # . . `) }) ``` Run your code in the simulator or download it to your @boardname@ to see what happens! ## ~avatar avatar Excellent, you're ready to continue with the [challenges](/lessons/snowflake-fall/challenges)! ## ~