Why do anemonies like power heads so much? I have 2 anemonies and when I put them in my tank both headed for the power heads right off. 2 days ago I put my rbta in my larger tank and like it did in my nano it went right for the power head but this time it went right through it

. It's gone now. But it got me thinking why do they like the power heads? Is it a sound it makes or some vibrations? Any guesses it insights?