I'm not sure what happened but I was exploring my world and saw large areas where there is dead grass. I hadn't altered the blocks myself, all the animals are accounted for in the water, and never used this world in multi-player mode D: Anyone else experience this or know what may be cause?

Not sure if may be relevant, but this is the same world I have been adding dirt with torches to grow more grass near the aquatic animals...

(ipod 4g in survival mode)