Do you know anything on leeche traps?

Question:the small lake in neighborhood has developed leeches..i know it is a natural part of nature and cycles but i heard of a trap you can make to reduce the number...something like a slug trap...anyone know

Answers:
I don't think this is going to make a big dent in the population but when I need leeches for bait, I tie liver in a piece of an old Tshirt. Tie it to a line and leave it in the water about 10 minutes, slowly pull it to shore with leeches galore. RScott