Why do Zoos detach?

[Gatorfreak]

About a month ago I got a rock with Zooanthids on it. Several have "let go" or detached themselves since. One has actually got footing in the sand bed and has been living there about 2 weeks. Couple questions... Why do they do this? And how can I help the ones that become free-floating to reattach somewhere?

Thanks

 

[electrikat]

That's how they spread to reproduce. When it gets too crowded where they are they move. You could either help them reattach by using superglue gel or putting them on a rock and loosely wrapping some bridal veil material around it. Make sure they are not in an area of high flow til they attach.