Snakes and garden ponds

[nancy]

This is somewhat OT for orchids, but I am hoping that somebody has a solution that I can try.
My little (24 gal.) garden pond *was* inhabited by several large fantails and comets, very long-lived fish. I had noticed a few ribbon snakes hanging around basking, and didn't think much of it until I realized that all of my fish had vanished! The biggest ribbon snake is also the biggest one I've ever seen, about 3' long and as thick as my wrist. He will be getting even larger after those nice fish dinners (one of the comets was as long as my hand!).
So, we pelted them with BBs, squirted with the hose, and haven't seen them for a few weeks, so the other night bought a dozen little comets and restocked.
All was well yesterday morning, but when I got home from work, it was to a deserted pond. Grrrr!
I've put out some "Snake-Away" (essentially mothballs) with no result.
Please, any suggestions?
Thanks - Nancy