Ricordia about to split but at night - It shrinks a lot

[I have some ricordia that is doing very well and is about to split for the first time in my tank. My question has to do with lights out. It becomes very very small when the moonlights take over. I know this thing really likes the light but is it supposed to shrink up a lot?? None of my other coral seems to hide at night as much as my ricordia does.]
 
Top