In one of my pond jars an explosion of a Stylonychia (I think) population has resulted in a complete decimation of a group of tiny ciliates they were feeding on. I found a lone Coleps on the slide and watched as many of the larger ciliates, quite likely hungry, approached and then rapidly retreated. I wonder what avoidance mechanism was at work here?
https://youtu.be/8NCAggacX10?t=45