We were at Apollo Beach, Florida, visiting the Tampa Electric Environmental Education Facility. The power plant there discharges warm water and hundreds of manatees and other fish gather there to enjoy the warm water. We walked out on a pier and saw lots of stingrays. Many of them were jumping up out of the water. Often times they would jump 1-2 feet out of the water. This jumping was observed many times over about a half hour period of time. Other people were there, too, and no one had ever seen this before. What made these stingrays jump?