In World War 1, to fly slightly off the straight-line course towards an enemy aircraft, as the machine guns on early aircraft did not allow firing through the propeller disk
A crab is a sea creature with a flat round body covered by a shell, and five pairs of legs with large claws on the front pair. Crabs usually move sideways. Crab is the flesh of this creature eaten as food. Any of 4,500 species of short-tailed decapod, found in all oceans, in freshwater, and on land. Its carapace (upper body shield) is usually broad, and its first pair of legs is modified into pincers. Most crabs live in the sea and breathe through gills, which in land crabs are modified to serve as lungs. They walk or crawl, generally with a sideways gait; some are good swimmers. Crabs are omnivorous scavengers, but many are predatory and some are herbivorous. Two of the largest known crustaceans are the giant crab of Japan (13 ft, or 4 m, from claw tip to claw tip), a spider crab; and the Tasmanian crab (up to 18 in., or 46 cm, long, and weighing more than 20 lbs, or 9 kg). Other species are less than an inch long. Well-known crabs include the hermit crab, edible crab (Britain and Europe), blue crab, Dungeness crab, fiddler crab, and king crab. blue crab Crab Nebula Dungeness crab fiddler crab hermit crab horseshoe crab king crab Japanese crab Alaskan king crab spider crab