Falling Sand Disappearing

After some seconds the falling sand disappears, while it is riding an other entity, here is the command: "/summon FallingSand ~0 ~3 ~0 {CustomName:"Ditto",CustomNameVisible:true,TileID:157,Time:1,PersistenceRequired:1,Riding:{id:Pig,CustomName:Ditto,CustomNameVisible:true,ActiveEffects:[{Id:14,Amplifier:2,Duration:10000000}],Silent:1b}}"