Mosquito Patrol

Getting Set Up

Once you open Scratch, you’ll see a screen like the one below.

  • Look for each of the following parts and remember them.

The Stage

Scratch window with the stage highlighted

What is the Stage?

This is where your Scratch programs run. It has:

  • One or more backgrounds (images on the background of the screen)

  • Any code blocks associated with it (we’ll get to this)

The sprite list

Scratch window with the sprite list highlighted

What is a sprite?

Any object that goes on the Stage is a sprite.

The sprite includes:

  • The image on the stage
  • Any alternative costumes (looks) it has
  • Any sounds associated with it
  • Any code blocks associated with it

The code blocks palette

Scratch window with the blocks pallet highlighted

Code blocks

Code in Scratch comes as blocks that you connect together to make programs. You choose blocks from the code blocks palette and drag them into the current sprite panel, then connect them.

There are ten categories of blocks. They are colour coded, and you can select each category from the list at the top of the code blocks palette.

The current sprite panel

Scratch window with the current sprite panel highlighted

What is the current sprite?

The current sprite is the one that’s selected in the sprite list.

The current sprite panel is where you can see the code, costumes, and sounds for the selected sprite.

Time to get coding! Go back to Scratch and click on the Scratch Cat in the sprite list. The cat is now the current sprite.

Go to the Events category in the code blocks palette, click the when flag clicked block and drag it onto the current sprite panel.


Then go to Looks in the code blocks palette and find the block


Drag it onto the current sprite panel, connecting it to the bottom of the other block, like this:


Now click the Start Program button and watch what happens!