The idea of birds carrying them on their feet, in their feathers, or in there throats is a lot more plausible to me than evaporation, or super flying fish eggs, or underground springs, or even alien spacecraft that jump from pond to pond spreading the eggs. My best guess if the waterfowl and quite possibly some of the larger game animals that walk into the water while drinking. They can travel a mile in little time at all. We have a lot more wildlife in Wisconsin than in Texas and it is pretty common knowledge that the birds carry the eggs. Next summer I may try to get some eggs to stick to my hand and transport them to another container just to see what happens. 5 minutes would be plenty of time for a bird to move from one body of water to another around here. With all the discusion about bullheads living for 24 hours out of water is it so hard to beleive the eggs could last for an hour under a birds wing?