A wild octopus surprised an Australian diver this week by suddenly, and quite dramatically, inflating itself with water, ballooning up like a parachute. Later, when the diver posted a video of the interaction online, she wondered whether the octopus was trying to intimidate her with its grandiose size. A team of marine biologists at the Birch Aquarium at Scripps Institution of Oceanography at UC San Diego gave one likely explanation. The video shows how the octopus used camouflage to blend its color and body texture with its habitat, the Scripps team said. When the animal sees the diver, the octopus spreads out its arms twice, likely to make itself look larger, the scientists added.“This behavior is used to say, ‘Look how big I am. You don’t want to eat me,’ to a predator,” said Caitlin Scully, a spokesperson at the aquarium.