Feather duster moving?

[Magma]

I have a Hawaiian feather duster, purple one..and hes been in his tube where i put him in the tank for a month or more now, no problems comes out, looks pretty...today i look and his tube seems kinda deflated so i figure whatever its looked like that before, and sure enough a few minutes later hes out showing off, i check the tank like 3 hours later and hes not in his tube hes on the other side of the tank sticking out the side of some live rock...

can they move? i thought they needed to be in the tube at all times...and i checked again just after lights out and hes in a totally different spot again...(original tube i bought him in is still in the same spot in my tank, it has not moved at all.

is he sick? or just not going to cooperate and stay where i want him?