Mine did too when I had them. I had quite a few of those starfish in my main display and had my harlequins in another tank plumbed off of the main system.
They were on a reverse lighting schedule, so at night all the asterina stars would come out onto the glass of the main tank and I would scrape them all off and wad them into a little ball and drop em in front of my harlequins. Worked great for me.
Also, look at online retailers for the purchase of the chocolate chip stars, unless u can work a deal with a local store for em.
I dont know if it makes a differnce, but the asterina stars I had were the ones with no green or red on them, they were completely tan across the whole body.