What is my Mushrooms doing?

I was feeding my tank this morning and noticed my hairy mushroom had closed itself inside out like a balloon. I have never seen it do this. Is it feeding? One in the back is doing the same thing. The ones in front are bouncing up and and down now like they are getting ready to do the same thing.

 

Yes , mine do that when I use to target feed them. its neat to watch. There trapping the food and moving it to there mouth.

 

thank you. this is so cool to watch. I have had them for over a year and have never seen this. I guess they did it at night before