Flies that have just been removed from the water.
fished in a sub surface manner to imitate or suggest sub aquatic species.
These species can include the nymph, chironomid
, and dognobbler.
Alternatively the wet area on the front of your trousers where you spilled
your coffee when a trout took your unattended blood worm while you were
having a break and did not retrieve your line.
Courtesy of Carl