The purpose of this mini-lab is to practice working with while loops (introduced in Chapter 7) and working with lists (Chapter 9).
Start out by adding three or more birds (available in the web gallery) to an otherwise empty world. Create a list containing all of the birds that you added. Now create an animation in which all of the birds take turns moving toward the camera by a small amount. Don't move each of the birds individually in your code. Instead, iterate through the list of birds using a "For all in order" block to create the animation.
Until now we have used the "loop" construct to create infinite loops. Another possibility is to use a while loop with the condition set to "true". Put your "For all in order" block inside an infinite while loop so the birds keep moving toward the camera until the animation is terminated by the user. THIS WILL BE IMPORTANT IN THE NEXT EXERCISE.
The effect should be that the birds are moved a bit closer to the camera each time through the list.
Once this function is written, you can easily modify your animation
from the previous exercise so that it terminates when the first bird
reaches the camera. Just replace the "true" in the while loop with a
call to your new function. (You might also have to throw in a "not"
from the world's list of functions. The loop should continue while
the birds have not reached the camera.)
In order to create the scary red screen effect, add an instruction after
your while loop that changes the light's color to red.