b/w i have found hard to get to host, just wait a few days to a week and if they dont host by then it may take more time or they may not host at all. it took mine about 2 weeks to even begin to notice the anemone and then i wake up one morning for class to see 2 heads sticking out from the tentacles. the bobbing action, is kind of like they are trying to host and protect the wall, im going to assume that they are doing this near the back wall because it is dark and they know nothing can come up from behind them. jsut give it time they will do what they want even if its not what you want.