koi pond behaivor

Question
i am a mississippi resident that has been trying to maintain a pond for my pet koi and goldfish with the pond being about a foot deep and containing about 13 fish, predominately koi with the oldest being 4 months old. Just recently i have noticed that one of the koi and one of the goldfish have migrated to a corner of the pond and have not showed a lot of activity or movement. Neither the koi or goldfish are older than 3 months. This puzzles me because they dont really seem to be sick. Its more like they are resting. If you could give some insight into this type of behaivor it would be greatly appreciated. I look forward to receiving your answer and thank you very much.

Answer
It's possible these guys are being picked on or ostracized from the group. If they aren't sick and still eat (but only a little) you may want to think about finding them a new home. They all have individual personalities and preferences even though they normally will get along.