We have an inground swimming pool that we haven't used in a few years (it's just too expensive for us to maintain at the present time).
Well it's almost June and the frogs are a' plenty. Our pool (covered, but with a top layer of about 2ft of water over the tarp) has become a pond/swamp for these little critters, and at night the sound is keeping us up (and our neighbors) all night long.
I'm tempted to start routinely dumping chlorine into the water that's on top of the tarp, but that will get almost as expensive as...maintaining a swimming pool ;-).
There really isn't anything we can do about the water on top of the tarp. All we have to keep the tarp sitting on top of the pool are a bunch of cinder blocks that weigh it down. In between the blocks the frogs can slip under the tarp and get access to the main pool anyways.