Molly rolling in food?

I keep my fish in my office, and since I don't work over the weekend(Fri-Sun i'm out) I decided to buy the slow release feeders instead of stopping by to feed them. After going to a couple different stores I decided to try the "Tetra weekend: tropical slow release feeder" The one I bought is a 5 day feeder. I figured I would drop it in Thursday morning and then resume regular feeding on Monday. Anyway, aside from eating it my molly seems to be rolling in it and rubbing it on herself. I've never heard of fish rolling in stuff(especially food) before. Can anyone explain?