When we bought this property and moved here in fall of 2009, we noticed hundreds if not thousands of bullfrog tadpoles in our pond, but heard no adults. The next spring after ice out, we could see dozens of larger tadpoles, the size that begin to change into frogs come summer. We were expecting lots of big frogs to eat. Nothing doing-we have 1 bullfrog presently. The tadpoles all disappeared before they became adults. We've never seen another tadpole since the summer of 2010. I'd like to understand what happened. Shoreline cover has always included some cattails and bulrushes. Underwater vegetation was non existent the first 2 years. Now, there's lots of elodea and some sago is moving in. What happened to the frogs is a mystery to me.