- Rubber Grubs are a super soft, buoyant imitation maggot that can be used to produce a critically balanced or popped-up bait. They are best used in conjunction with real maggots when a slow sinking or balanced hook bait is required, e.g. when fishing over bottom weed or when fish are taking on the drop. They are also useful where small fish are a nuisance constantly tearing real maggots off the hook. Alternative they can be used to pop up a bait, when matched with an appropriate hook size.