I've had those too, James - right inside the mouth area. In my case it was BG and YP - and as soon as I stocked FHM and crayfish into the pond they quit showing up. I'm assuming that I needed smaller fish able to prey on such small leeches. Didn't seem to be causing the fish any issues I could determine, but I didn't like them messing with my babies.

Many men go fishing all of their lives without knowing that it is not fish they are after. ~ Henry David Thoreau

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