Fish in a Bucket

If you fish one place long enough you end up with a pretty intimate knowledge of the bottom. You remember where the stumps and the rocks are, the channels and drop-offs. This is especially true with carp fishing. When the surface is rippling and the water is a little bit cloudy, it's easy to spot a big carp, and only a dozen heart pounding casts later realize to your great embarrassment that you have been trying to catch a log.
Unfortunately, on heavily used waters, not all the submerged obstacles are natural. About three quarters of the way along one of my favorite flats is a small red bucket. The type of bucket a child would use to build sand castles at the beach. The other day as I approached this spot I saw a suspicious cloud of mud. Curiously I approached, and saw a carp feeding with it's head stuck completely inside the bucket! I must have waited poised for a minute or more. Each time I thought the fish was done I'd see the tail quiver and the head disappear into the bucket again. When it finally emerged, I made sure that my worm fly was the first thing it saw. You can guess how that turned out:
Sure made me wonder though, what was in the bucket?