I recently fixed the waterfall from my bog filter and it has attracted these interesting albeit annoying guys. They croak all night really loud and like to swim around the plants in my pond.
I just love your pond. I have had one for 10 years. I have has much wild life visitors through out the years. Gray herring, muskrat, coons. LOL I live in a subdivision where the houser are close, but that does not stop the wildlife. Enjoy