And space-based technology guided new "smart bombs" with such accuracy that the hit ratio plummeted to 1 in 10.

Their work involved training pigeons for use by the U.S. Navy, teaching the birds to guide bombs.

These include scouting targets and standing by to illuminate them with laser beams that precisely guide missiles and bombs to the most important ones.

"Well, I met with the guy who guided the 'car bombs' into the targets."

Unlike laser beams, which are used to guide missiles and bombs to their targets, millimeter-wave radiation easily penetrates smoke, dust and other obstructions.

The guidance system had to work using the same principles as the US Paveway guided bombs.

In addition, all Predators delivered next year will come with infrared devices that can be used to guide bombs into targets.

Even guided long-range bombs can be risky to use in dense cities.

In the Balkans, clouds have blocked pilots from beaming their lasers to targets on the ground to guide bombs to their targets.

Her first husband Keller Breland also came to study with Skinner and they collaborated with him, training pigeons to guide bombs.