Japan's All-Nippon Airways has discovered that by menacing-looking eyes painted on the engine intakes of its jet aircraft frighten away birds and prevent collisions.

The magazine International Wildlife reports that in a controlled experiment, the Japanese domestic airline painted eyes on 26 of its Boeing 747's and 767's, and left the rest of its fleet without the bogus eyes.

At the end of the one-year test period, an average of only one bird had hit each of the engines adorned with painted eyes. Each unpainted engine, however, had been struck by an average of nine birds.

All-Nippon Airways estimates that the reduction in bird strikes during the testing period reduced the damage to its aircraft from $910,000 to $720,000. Consequently, All-Nippon plans to paint eyes on all its large-body aircraft.