Do hammers close at night?

I've only had my hammer for two nights now.

The hammmer opened yesterday and never stopped getting bigger and opening, not even when the moonlights on.

Today it looked even bigger so I feed it a little mysis. The mysis slowly got taken in and that was that.

Well the lights turn off and moonlights turn on and I notice one side of the hammer close up and then the whole thing got really small now, like I just got it out of the bag. Is this normal or is something wrong?

 

my hammer closes every night and I have never been able to get it to accept food... it started with 2 heads and now it has 5.

 

Thanks, I didn't know that they closed because it didn't close the first night.

Yeah the mysis just kinda layed on the top at first and slowly the tentacles started to retract while the others pushed it in the middle and finally it was gone!

 

Is it a branching type of hammer or the anchor type? It could probably be pooping. My torch and bubble close up at night. As long as its fully extending during the day, there shouldnt be any problems. Or it could also be producing new heads.

 

Its not the branching type. Kinda just has a big bottom if that makes sense?