I used to tolerate them, but when they drilled some of my bass in the head that were too big to eat I decided they could go eat at the public lakes.

At my one pond in particular, (the other is so close to the house they don't bother it)they usually show up at dawn and dusk. Fortunately for me that is also feeding time, and if I see any they are scared off by my 100 pound dog and I. After awhile they pretty much get discouraged, but will give it one more try every few weeks or months.

I too don't like the parasites as I have lots of snails in the pond. Chasing off works for me. I'm also self employed at the house and I work in a shop facing the pond. The dog lets me know even if there is a crow walking on the lawn.

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.