Thousands of Humboldt squid, also known as jumbo flying squid, have invaded the waters of San Diego, California, menacing(脅威を与える)scuba divers and washing up on beaches. The aggressive, carnivorous creatures have razor-sharp beaks(口先、くちばし)and toothy tentacles and have been known to attack humans. They typically inhabit the deep waters off of Mexico, and it is unclear why they are swarming(群れをなして動く、うようよする)off the Southern California coast. Research suggests that the squid may have established a permanent population in the waters near California, at depths of 300 to 650 feet, and that the swarms occur when their prey moves to more shallow water.