With some of my groups working on patterns, I asked what colors they wanted to use and started a pattern for them to continue.
For the most advanced group, we had a discussion about patterns beforehand and made a list of all the combinations we could think of. Then each kid had to choose a pattern to use when making their worm. One student chose the ABBBC pattern and another chose an ABB pattern. They did so great with this!
Two of my students decided they wanted to make "baby worms"....they turned out super cute as well!
This is how I set up the activity for my beginner group. I made pictures of the materials to put on the PECS book.
I would hold up the different choices of hearts and have a student use the pictures to create a sentence for what color heart they wanted next. After reading the sentence, I offered up the hearts and waited for them to reach for the heart (to ensure they reached for the same color they requested).
Then, when they needed glue, I would hold the glue and wait for them to request that as well. After a couple turns, I wouldn't hold up the materials for them, to see if they could request on their own.
For all my students, this activity allowed for lots of language and questions. What are we making? What colors do you want to use? How many different colors are there? What are these (point to antennas....since we studied these in our bug science unit)? What is this? (pointing to any of the materials we used)....etc.