To some fishermen using egg patterns is not true fly fishing but the egg pattern works excellently under a bung. If you are imitating the natural food of your target fish then using eggs is fly fishing. The art of matching the colour and size that are being eaten is an art form just like matching the hatch of emerging dry flies fish them on the drop, in clear water, fish dead slow otherwise on all depths.

Can be useful when the fish have seen pretty well most other patterns