I live in central Florida. I have a screened pool in my backyard. There is also a pond in my backyard. I am attaching a picture of these little critters that are floating in my pool. I think they are even reproducing or giving birth to their young ones in my pool. I have checked my enclosure for any cuts in the screen that may be leaving these critters in and there is none. My screen/mesh size is 20x20, which I believe is the smallest around for preventing bugs to come in. If anybody knows how to combat these baby's please let me know. Thanks.