We start colliding turtles from a new project.
Here are the guidelines:
1) Create 50 turtles [Hint: use a "when setup pushed" in the World page]
2) Have the turtles move around Spaceland [Hint: use a "when forever toggled" in the Turtle page.]
3) Upon colliding with another turtle, have the turtle change a trait. [Hint: use a collision block on the Turtle page.]
4) When you are done, save and share your project.
You can use the on collision block, and the set my trait to value.