I think that it is great that you are looking to fit the needs of every learner in your classroom, its so important that teachers give students who are nonverbal opportunities to learn in a way that fits their abilities. While I volunteered at a school with half of the students being almost or completely nonverbal and half of the students being fully verbal, we did a lesson on butterflies that was differentiated for every learner. We began by reading a book with pictures that described the butterfly lifecycle. After the reading we had the students cut out the stages of the butterfly lifecycle. We had standard and specialized scissors available for those who had the motor skills to use them and for those who did not we assisted them in cutting with the specialized scissors. I am not sure of the motor skills of your students but some of the students in my class were unable to handle the paper without ripping it and glue it onto the sheet so we had the same worksheet laminated with Velcro that they were able to stick the images on to show their understanding. Music is also known to help students with disabilities engage in a lesson and I found a really cute song about the butterfly lifecycle called Butterfly, Butterfly! On YouTube that you may want to include.