I agree that a note to the parents might be in order. But, you should not depend on it getting home with the kids. It should go in the mail, or the district wide news letter, perhaps in an upbeat: This is what we are doing: We are providing a flock of chickens that can teach our children valuable lessons (insert how the bird's care can be used to teach math skills, science, reading) as well as compassion, animal husbandry. Finish with a note that there have been some issues with the birds being mistreated, and it would be a shame to loose this valuable educational opportunity for the kids.