Subject: Pool creature?
Geographic location of the bug: Tennessee
Time: 08:17 PM EDT
Your letter to the bugman: My sister had me come look at her pool over these things eating the tadpole eggs in the filter.
How you want your letter signed: Kitty
This is a Water Tiger, the predatory larva of a Predaceous Diving Beetle. These larvae breathe through a siphon at the tip of the abdomen that breaks the surface of the water.