Stealth works

Bats. Bats were the first visual proof I had that stealth really worked. We had deployed thirty-seven F-117As to the King Khalid Air Base, in a remote corner of Saudi Arabia, out of range of Saddam's Scuds, about 900 miles from downtown Baghdad. The Saudis provided us with a first-class fighter base with reinforced hangars, and at night the bats would come out and feed off insects. In the mornings we'd find bat corpses littered around our airplanes inside the open hangars. Bats used a form of sonar to "see" at night, and they were crashing blindly into our low-radar-cross-section tails. After all those years of training, we certainly believed in the product, but it was nice having that kind of visual confirmation, nevertheless.

Colonel Barry Horne, F-117A pilot in "Operation Desert Storm", quoted in: Skunk Works by Ben R. Rich and Leo Janos.

And here's how the bats will probably see the new F-22 fighter jet...