Behavior Classroom Management Tool for Teachers. This would also work great in a homeschool environment. Quiet critters only come out of their jar when students are working quietly. They are a great tool to help control sound level and focus in a fun way. Each set includes 15-16 critters and their safe "sound proof", plastic 16oz jar. No two critters are alike. I have stopped using sparkly critters due to the eyes not adhering well and falling off.