Astrenia eating Zoos?!

Found one astrenia star in my little zoo colony. Looked like he was eating them so he got voted off the island. Well he wasn't the only one. Pulled 3 different ones off the zoos. But the rock I purchased the zoos on is decimated. Some got eaten and some I have found floating around. Just glued about 6 or 7 heads to a different area that I found free floating. Lost most of their color. Maybe they will turn around but thinking that the stars will find them again. Have had astrenia since I can remember but never thought they were harmful. Now I am picking ones out of their tank for their first time.

Anyone else ever had this experience? :help:

Here is a pic of them first one is caught. Now this rock is bare!!!