The dark red color and looming posture of this Octopus tetricus likely signals menace to another octopus nearby, say scientists who studied 186 octopus interactions in 52 hours of underwater video.
David Scheel/Current Biology
hide caption
When the gloomy octopus of Australia turns dark and towers threateningly over his neighbor, he's likely signaling aggression, scientists now say. Neighbors get the message — they turn pale and flee.
A Shiite militia fighter stands in front of a damaged building in Tikrit, Iraq, in April, just days after Islamic State fighters were driven out. Many of the city's Sunni residents have now returned, but the armed Shiite groups remain. For now, the Sunnis and Shiites are mostly getting along.
MOHAMMED SAWAF/AFP/Getty Images
hide caption
Defense Secretary Ash Carter leaves a news conference at the Pentagon on Thursday. In an interview with NPR, Carter said a top priority was to drive the Islamic State out of its headquarters in Raqqa, Syria, and from Mosul, Iraq, that country's second largest city.
Cliff Owen/AP
hide caption
The dark red color and looming posture of this Octopus tetricus likely signals menace to another octopus nearby, say scientists who studied 186 octopus interactions in 52 hours of underwater video.
David Scheel/Current Biology
hide caption
